Sunday, August 8, 2021

Victoria records 53 days with no measurable rainfall - the third longest such dry streak on record

 Following the unprecedented heat wave in late June 2021, temperatures in Victoria returned to normal, but the dry sunny weather continued.  

Victoria Gonzales received no measurable rainfall in July.  That is the 7th time that Victoria has experienced a July with no measurable rain (the other times being 1914, 1922, 1926, 1958, 1984, 2018).  It is also the 12th time overall that Victoria has had a calendar month with no measurable rain.  

In all, there was no measurable rain recorded at Victoria Gonzales from June 15 to August 6 - a total of 53 days.  That makes it the third longest such dry streak recorded in Victoria over the past 120 years.  The longest dry streak was 63 days, from June 15 to August 16, 1926.  The second longest was 54 days from July 17 to September 8, 1986 - many residents will remember that year for the great weather at Expo 86.  

The chart below shows the longest dry streaks ever recorded in Victoria.  Of note, 4 of the 10 longest dry streaks occurred in the 1920s, which was the driest decade on record in Victoria for both average annual precipitation (601 mm) and average summer rainfall (34 mm for the June to August period). The past 10 years (2011-20) was the second driest decade for summers, with an average 36 mm of rain, which could indicate the beginning of a trend towards even drier summers that most climate models predict for our area as a result of climate change.  Conversely, none of the longest dry streaks was in the 1990s, which was one of the wettest decades (along with the 1930s) in Victoria, for both total annual precipitation and summer rainfall.  



Thursday, July 1, 2021

Heat Wave June 2021: Victoria breaks its all-time high temperature record

The heat wave that Victoria and the surrounding region just experienced was truly historic.  Weather historian Christopher Burt described it as “the most anomalous regional extreme heat event to occur anywhere on Earth since temperature records began" roughly 150 years ago with the beginnings of modern meteorology.  Never before have so many all-time temperature records been broken by such a large margin in one region by a single event.  According to international weather records researcher Maximiliano Herrera, more all-time heat records were broken by at least 5 C in the June 2021 heat wave than in the previous 84-plus years of world weather recordkeeping.  A group of international climatologists estimated that this heat wave was a 1 in 1,000 year event for our region, and that even with continued climate change, it will remain a very rare event.

On June 28, 2021, Victoria recorded its all-time maximum temperature: 39.8 C.  That completely shattered the old record of 36.0 C set on July 11, 2007.  Many other locations in B.C., Washington, and Oregon also broke new all-time maximum temperature records.

Below are the June 25-29 daily high temperatures around the Victoria region:


The numbers are extraordinary.  Most locations broke their all-time temperature record on June 27, then broke it again on June 28.  Typically, when an all-time temperature record is broken, it might be by a fraction of a degree.  In this case, Victoria Gonzales beat its old record by 3.8 degrees, while Victoria Airport beat its old record by 3.1 degrees.  

The chart below shows hourly temperatures at Victoria Gonzales during the heat wave, compared with the average daily maximum and minimum temperatures in late June.  The peak temperature of 39.8 C at about 3 pm on June 28th was nearly 20 degrees C above the average!  Even the overnight lows on June 26th and 27th were higher than the average daily maximums.  

Some specific patterns are notable:

On June 26th, an on-shore sea breeze developed in the late morning and early afternoon that prevented temperatures at Gonzales from getting really hot.  The temperature peaked at 32.5 C between 11 am and noon, but then plunged to 23.4 C by 1 pm as the sea breeze kicked in.  

A sea breeze also developed on June 27th, but much later in the day.  The temperature peaked at 38.3 C between 2 pm and 3 pm.  It was still 35.9 C at 6 pm, but then a sea breeze developed and the temperature plunged 10 degrees in an hour, to reach 26.2 C at 7 pm.

The late evening, overnight, and early morning period between June 27th and 28th was remarkably warm.  After the early evening sea breeze on June 27th, the temperature warmed again, and was still a remarkable 28 C at midnight.  For most of the night, the temperature remained above 24-25 C, with just one hourly recording at 4 am  when the temperature dropped to 22.1 C.  By 7 am, the temperature was back up to an amazing 29 C, and it continued to increase sharply from there.

Also of note is the dramatic fall in temperatures on the evening of June 28th.  After hitting its peak of 39.8 C around 3 pm, the temperature remained a very hot 37.4 C at 6 pm, but then fell to 15.6 C at 6 am on June 29th - a drop of nearly 22 degrees C in 12 hours.  By the morning of June 29th, the heat wave was a distant memory, with a 10 am temperature of 16.2 C compared with 34.8 C at 10 am on June 28th.  That's a remarkable 18.6 degree C temperature change in 24 hours!  



In addition to these official Environment Canada weather stations, victoriaweather.ca (operated by University of Victoria climatologists) has a more extensive network of weather stations in the region.  Roughly 20 of these sites topped 40 C on June 28.  The table below shows the hottest of these in each municipality:


The chart below shows the annual maximum temperature at Victoria Gonzales over the past 120 years. The new record maximum set this year clearly stands out!



This next chart looks at the peak temperature for just the 10 hottest heat waves ever recorded at Victoria Gonzales:



Again, the June 2021 heat wave clearly stands out as something extraordinary.  All the previous heat records were in a fairly narrow band between 33 C and 36 C, while the extreme heat we just experienced was nearly 4 degrees higher!

As a result of the heat wave, June 2021 ended up being the warmest June on record at Victoria Gonzales.  If you look at the period from June 1 to June 24, prior to the heat wave, the mean temperature was 14.8 C, which was warmer than the 30-year average of 14.3 C, but not unusually so - the mean temperature for June 1-24 was warmer in 10 of the previous 30 years.  However, the heat wave bumped up the mean monthly temperature for June 2021 to 16.6 C.  That's 0.5 degrees warmer than the previous warmest June, when it averaged 16.1 C in 2015.  

So what caused this extraordinary event?  It was the result of an unusually large wave in the jet stream, which may have been caused by a tropical system interacting with the jet stream in the eastern Pacific. This created a strong upper-level high pressure ridge over the BC Interior, which results in sinking air and warm temperatures.

Victoria gets this situation fairly often during the summer, although this was already an unusually strong ridge – one of the strongest ever measured. The heat was then amplified by a low pressure trough approaching the coast at just the right time and location to maximize this event. The pressure differential created a strong southeasterly flow from the Interior out to the coast. The warm air from the Interior was heated even more as it crossed the Coast Mountains and compressed as it descended towards the coast (this is a phenomena like the hot Santa Ana winds in Southern California).

On a typical hot day in Victoria, rising warm air over the land draws in cool air from the Strait of Juan de Fuca, resulting in a cooling sea breeze – especially for areas near the Strait like Esquimalt, James Bay and Fairfield. Victoria Gonzales, being so close to the Strait, is often one of the cooler spots in the region on hot summer days, several degrees cooler than areas further inland. In this case, the strong northerly breeze that resulted from the flow of hot air from the Interior blocked the sea breeze from developing. As a result, Gonzales, with a maximum temperature of 39.8 C on June 28, was the hottest of all the Environment Canada recording sites in the region.

Another factor may have been the time of year when this happened. Many people seemed surprised about how early in the summer this heat wave occurred, given that we usually get our warmest average temperatures in late July or early August. However, if you look at the top 10 hottest days ever recorded in Victoria, 6 of them occurred between June 25 and July 1. It may be that the very long days and strong sun this time of year (close to the summer solstice) contributes to these heat waves.

So the unprecedented heat was the result of all these factors combining in just the right way to create the “perfect” extreme heat situation. This combination of events is unlikely to be repeated any time soon.

Given the extraordinary and historical nature of this heat wave, it is worthwhile looking at some of the other temperatures recorded elsewhere in B.C., Washington, and Oregon.

First, some maximum temperatures for the rest of Vancouver Island, with several locations topping 40 degrees C.  Port Alberni, as is typical, recorded the highest temperature on the Island, with 42.7 C.


Next, several locations in Metro Vancouver, the Fraser Valley, Howe Sound, and Sunshine Coast.  Vancouver Harbour, right near the water and with westerly breezes, was one of the "cooler" spots at 33.8 C.  However, several locations in Metro Vancouver were at or above 40 C.  Temperatures were even hotter - around 43 C - in Abbotsford, Squamish, and Whistler.  


Both Seattle (42.2 C) and Portland (46.7 C) broke all-time maximum records.

Finally, in the B.C. Interior, several locations reached or exceeded the old Canada-wide all-time maximum record of 45.0 set in Middale and Yellow Grass, SK in 1937.  This included Lytton reaching an amazing 49.6 C to set a new Canadian national temperature record, and the record for the highest temperature ever recorded north of 45 degrees N.  


Tuesday, June 22, 2021

Spring 2021: Drier and slightly cooler than normal

 Meteorological spring consists of March, April, and May.  Spring 2021 in Victoria brought lower rainfall and slightly cooler temperatures than normal.  The spring started out cooler than normal in March, followed by a slightly warmer than normal April, and ended with a cooler than normal May.  Meanwhile, all three spring months were drier than normal in 2021.


The mean temperature this past spring at Victoria Gonzales was 9.8 degrees (ave. high 13.3 & ave. low 6.4), which is 0.3 degrees below the 30-year average of 10.1 C.  March was 0.6 degrees cooler than normal, April was 0.4 degrees warmer than normal, then May was 0.6 degrees cooler than normal.      

The chart below shows the daily maximum and minimum temperatures at Victoria Gonzales during spring 2021, compared with the 30-year averages.  The most obvious feature is the "heat wave" that Victoria experienced in mid-April.  Temperatures were in the 20s for 5 days, peaking at 24 C on April 17.  For much of the rest of spring, temperatures were generally below normal.


There were no days during Spring 2020 when the overnight low fell below freezing.  On average, Victoria sees just 0.6 days each spring with a low temperature below 0.  The coldest temperature of the spring was March 15 when the temperature dropped to 1.6 degrees.  The warmest day of the spring was 24.0 degrees on April 17.  That is unusually early for the warmest day of spring, in part thanks to a cool May.  Spring 2021 in Victoria saw no days with temperatures above 25 degrees, compared with the average of 0.5 25-degree plus days each spring.


Max & Min Temperatures in Victoria, Spring 2021


Victoria received 83 mm of precipitation during the March to May period.  That's about 72% of the 30-year average spring precipitation of 115 mm, making it the 25th driest spring at Victoria Gonzales in 108 years - in other words, drier than normal, but not exceedingly dry.  March saw 40 mm of rain - just 72% of normal, April saw 22 mm of rain -  just 65% of normal, and May saw 21 mm - 80% of normal rainfall.  

Spring 2021 also saw fewer than average days with measurable rainfall: just 27 days compared with the average of 33.6.  There were 9 days in March, 7 days in April, and 11 days in May with measurable rainfall.  


The chart below shows daily precipitation during spring 2021, and compares the cumulative precipitation with the 30-year average.   Cumulative rainfall stayed below average throughout throughout the spring.  March 24, with 15.4 mm, was the wettest day of the spring.  March 28, with 11.6 mm, was the only other day during the spring with more than 10 mm of rain.



Daily & Cumulative Rainfall in Victoria, Spring 2021



The chart below compares the precipitation amounts in Victoria this spring with other locations in the region.  While Victoria Gonzales typically receives the lowest amount of rainfall in the region, in spring 2021, Victoria Airport was actually drier.  While spring rainfall was 72% of normal at Victoria Gonzales, it was just 32% of normal at Victoria Airport and 44% of normal in Vancouver.  Looking at this another, Vancouver typically gets more than 3 times as much rain in the spring as Victoria does, but in 2021 it received less than double Victoria's rainfall.  Seattle received 52% of its normal spring rainfall.    

Regional Comparison of Spring 2021 Rainfall


Wednesday, March 3, 2021

A look at Winter 2020-21 in Victoria

Meteorological winter is from December 1 to February 28.  Winter 2020-21 in Victoria brought close to normal temperatures overall, and above average rainfall and snowfall.  

The mean temperature this past winter at Victoria Gonzales was 5.9 degrees, which is just 0.1 degrees warmer than the 30-year average of 5.8.  The average daily maximum for winter 2020-21 was 7.9 degrees (right on the 30-year average), while the average daily minimum was 3.9 (versus the 30-year average of 3.7).  The winter started out mild in December and January, but a cold spell in mid-February brought the overall temperature for the winter much closer to the long term average.  December was 0.9 degrees warmer than average and January was 0.8 degrees warmer than average, but February was 1.5 degrees colder than average.     

The chart below shows the daily maximum and minimum temperatures at Victoria Gonzales during winter 2020-21, compared with the 30-year averages.  The first half of the winter was generally milder than average, with the exception of a short cold spell in mid-December.  The first half of January was especially mild, but that was followed by another short cold spell in late January.  Temperatures rebounded in early February, only to plunge to the coldest levels of the winter in mid-February, with two days when the temperature did not go above freezing (February 11 and 12).  The warmest temperature of the winter was 14.1 degrees on January 15, while the coldest overnight temperature was -4.0 degrees February 11.

Victoria Gonzales saw 6 days this winter with overnight lows below freezing, versus the long-term average of 9.6 days.  Interestingly, there were no days below freezing until quite late in the winter - February 9 - then Victoria saw 6 days in a row with overnight lows below freezing during the February cold snap, from February 9 to 14.  


Daily Max & Min Temperatures in Victoria, winter 2020-21




Victoria received 380 mm of precipitation from December to February, 42% more than the normal winter precipitation of 267 mm.  December was the wettest month with 157 mm (60% above the average of 98 mm).  January was only slightly wetter than normal, with 111 mm versus the normal 105 mm.  February was also much wetter than normal, with 113 mm - 77% above the normal 64 mm for the month.

Winter 2020-21 also saw more days with measurable precipitation than the 30-year average.  There were 56 days with greater than 0.2 mm of precipitation versus the long term average of 46.4 days.  In other words, there was at least some rain (or snow) on 62% of days during winter 2020-21.  December saw 20 days with precipitation (versus the normal 16.8), January saw 17 days (close to the normal 16.6), and February saw 19 days (versus the normal 13.0 days).  


The chart below shows daily precipitation during winter 2020-21, and compares the cumulative precipitation with the 30-year average.  From about mid-December onward, cumulative seasonal precipitation was well above average.    

December started out relatively dry (with the exception of 18 mm of rain on December 8), but mid to late December saw quite a bit of rain.  This included a deluge on December 21 which brought 55 mm of rain, making ti the second wettest day at Victoria Gonzales in the past 15 years.  Early January was quite wet, followed by a drier period in late January and early February.  The second half of February turned quite wet (and at times snowy).  





The chart below compares the precipitation amounts in Victoria this winter with other locations in the region.  Thanks to the Olympic Mountain rainshadow, Victoria Gonzales is typically much drier than other locations in the region,  but for winter 2020-21, the differences were less than normal, especially compared with Victoria Airport and Vancouver.  That is because Victoria's winter precipitation of 380 mm was 42% above normal in 2020-21, while Victoria Airport and Vancouver were both much closer to normal.  

The Victoria Airport received 402 mm. Typically, the Airport receives 43% more winter precipitation than Victoria Gonzales, but this year the difference was much less thanks to much higher than normal rainfall at Gonzales versus close to normal amounts at the Airport.  Vancouver received 558 mm of precipitation this winter - about 47% more than Victoria.  Normally, Vancouver receives more than double Victoria's winter precipitation, but again, Vancouver was much closer to its normal amount this year, while Victoria was much higher than normal.  Seattle received 510 mm of precipitation this winter, about 34% more than Victoria.  Like Victoria, Seattle was significantly wetter than normal this winter.  


Comparison of Winter 2020-21 Precipitation


Victoria received 28 cm of  snow in winter 2020-21.  That's double the normal winter snowfall of 13.8 cm.  All of the winter snow fell during 4 days in February, with most of it (22 cm) falling on  February 13.  That one February snow event was enough to make it the snowiest winter in Victoria in the past 10 years.  The number of days with snow on the ground was also above normal, but only slightly.  Victoria saw 4 days with at least 2 cm of snow on the ground this winter versus the 30-year average of 3.2 days.

Overall, winter 2020 was  close to normal for sunshine.  However, the seasonal total masks the fact that December was sunnier than normal, while February was cloudier than normal.  Typically, the amount of sunshine during the winter in Victoria increases from December to January to February, but this winter the amount of sunshine was fairly similar in each month.

The table below shows the number of mostly sunny days (>80% of possible sunshine), partly cloudy days (20-80% of possible sunshine), and mostly cloudy days (<20% of possible sunshine) during winter 2020-21.  Overall, the winter total was fairly close to normal, with December having more sunny days than normal, which offset February's fewer than normal sunny days.




Saturday, January 2, 2021

2020 weather in Victoria: year in review

Overall, Victoria's weather in 2020 was wetter than normal, but with close to average temperatures.

The mean temperature at Victoria Gonzales for 2020 was 10.7 degrees C, the same as in 2019 and right on the 1991-2020 30-year average.

Just 4 months had above average temperatures in 2020.  January was slightly (0.1 degree) above normal, while May, September, and December were each about 1 degree above normal.  Conversely, there were 8  months with below average temperatures in 2020.  March was the most unusual, with temperatures averaging 1.2 degrees below normal.  The other months were all less than 0.5 degrees below normal.  

The warmest temperature of 2020 was on August 16, with a temperature of 29.5 C.  There were 12 days in 2020 with daily maximums above 25 degrees, compared with the average of 9 days.  There were brief warm spells in May (peaking at 27.8 C on May 10), July (peaking at 29.1 C on July 26), August, and September (peaking at 29.4 C on September 10).  

The coldest temperature of 2020 was -5.7 C on January 14.  That was the coldest temperature recorded at Victoria Gonzales in more than 6 years.  There were 8 days in 2020 when the temperature went below 0, just less than the long-term average of 9.5 days.  Of those days when temperatures dropped below freezing, 6 were in January while 2 were in March.

The chart below shows the daily maximum and minimum temperatures at Victoria Gonzales in 2020, compared with the long-term normal temperatures.  You can the brief cold snap in mid-January, early March, and late October.  You can also see the occasional warm spikes, in May, July, August, and September.


Victoria received 837 mm of precipitation in 2020, nearly 30% more than the long-term average of 656 mm.  In fact, 2020 was the wettest year in Victoria in more than 20 years.  The 3 winter months - January, February, and December - were all wetter than normal in 2020.  January was particularly wet, with roughly double the normal precipitation, and it accounted for more than half of the surplus rainfall in 2020.   In contrast, the remaining 9 months saw close to normal rainfall overall, though March was significantly drier than normal while September was wetter than normal.

The chart below shows daily and cumulative precipitation at Victoria Gonzales for 2020.  You can see the heavy rainfall in January, and as a result, the cumulative rainfall quickly exceeded the 30-year average, and stayed above the average for the entire year.  


There were 139 days with measurable precipitation in 2020, compared with the normal of 132 days.  By far the wettest day of the year was December 21, when 55 mm of rain fell (at times mixed with a little wet snow).  In fact, this was the wettest day recorded at Victoria Gonzales in almost 5 years.  At the nearby University of Victoria weather station, 70 mm of rain was recorded, making it the wettest day there in 15 years.  There were 3 other days with more than 25 mm of rain, in January and early February.  On average, Victoria gets 2.9 days per year with 25 mm or more precipitation.   The longest dry stretch was 22 days, from July 12 to August 2.  This is a little shorter than the average summer drought period of 27 days with no rainfall.

The chart below compares annual precipitation at Victoria Gonzales in 2020 with other locations in the region.  Thanks to its rainshadow location, Victoria is typically drier than most other locations, and that was the case in 2020, though  not by as much as it usually is.  That's because precipitation at Victoria Gonzales was 28% above normal in 2020, while it was just 20% above normal at the Victoria Airport (in North Saanich) and 16% above normal in Seattle.  Vancouver actually saw precipitation that was 6% below normal in 2020, though the amount (1428 mm) was still 70% higher than Victoria.  On average, Vancouver Harbour gets 132% more precipitation than Victoria Gonzales.




Victoria had 23 cm of snow in 2020, compared with the average of 16 cm.  Nearly all the snow (22 cm) was in January, while there was just 1 cm of wet snow in December which did  not accumulate.  There were 5 days in 2020 with at least 2 cm of snow on the ground, all in January.  This is close to the annual average of 4.8 days with snow on the ground.

Sunshine was slightly above average in Victoria in 2020 thanks to above average sunshine in March, August, and December.  On the other hand, January and June were cloudier than normal.  



Thursday, December 3, 2020

Fall 2020 weather in Victoria

In this post, we'll review Fall 2020.  Meteorological fall is from September 1 to November 30.  Fall 2020 in Victoria brought close to normal temperatures and slightly above average rainfall.  

The mean temperature this past fall at Victoria Gonzales was 11.4 degrees, which is just 0.2 degrees warmer than the 30-year average of 11.2.  The average daily maximum for Fall 2020 was 14.4 degrees, while the average daily minimum was 8.4.  September was much warmer than average (16.0 versus 14.9), while both October (10.8) and November (7.4) were slightly cooler than average.     

The chart below shows the daily maximum and minimum temperatures at Victoria Gonzales during fall 2020, compared with the 30-year averages.  Early September saw a warm period that sent temperatures into the upper 20s.  The warmest temperature of the fall was 29.4 degrees on September 10.  There was another warm spell in late September and early October. Late October saw an unusual cold spell, with a record low maximum of just 7.4 degrees on October 23rd, and temperatures dropping to just 0.4 degrees overnight on October 25, the coldest temperature recorded this fall.  The  normal daily max/min in late October is 13/8 degrees.  



Daily Max & Min Temperatures in Victoria, Fall 2020



Victoria received 244 mm of rain from September to November, compared with the normal rainfall of 227 mm.  September was wetter than normal (45.6 mm versus normal of 30.2 mm) while October (80.8 mm) and November (117.8 mm) were both close to normal rainfall.  

While the amount of rain during fall 2020 was slightly above normal, the number of days with measurable rainfall was slightly below normal.  Fall 2020 saw 34 days with measurable rainfall (8 in September, 8 in October, and 18 in November) compared with the average of 37.9 days that Victoria usually sees during the fall.  The difference was due entirely to the lower than average number of days with rainfall in October (8 verses 12.8), while days with rainfall were close to average in the other months.  


The chart below shows daily precipitation during fall 2020, and compares the cumulative precipitation with the 30-year average.   September started out dry, but a rainy spell during the second half of the month pushed cumulative rainfall above normal.  There was a short dry spell in late September and early October (12 days without measurable rainfall), but then fairly consistent rain for the rest of the fall.  The highest rainfall amount was 21.2 mm on November 3.  Victoria Gonzales typically receives its first 25 mm rainfall day by mid-November.  There were no such days during fall 2020, although there were 3 days with around 20 mm of rain.



Daily & Cumulative Rainfall in Victoria, Fall 2020


The chart below compares the rainfall amounts in Victoria this fall with other locations in the region.  As is typically the case, Victoria Gonzales had the lowest amount, with a total of 244 mm.  The Victoria Airport received 314 mm - 28% more than Victoria Gonzales.  Vancouver received 460 mm - 88% more than Victoria.  Normally, Vancouver receives more than double the rainfall that Victoria gets in the fall.  Seattle received 318 mm - about 30% more than Victoria, and mostly due to a much wetter September in Seattle.  

Comparison of rainfall by month, Fall 2020



Fall 2020 was very close to normal for sunshine, and in fact all three fall months were close to the long term averages. Victoria received about 47% of possible sunshine during fall 2020, ranging from 58% in September, to 45% in October, and 33% in November.


The table below shows the number of mostly sunny days (>80% of possible sunshine), partly cloudy days (20-80% of possible sunshine), and mostly cloudy days (<20% of possible sunshine) during fall 2020.  This shows a fairly typical fall pattern for Victoria.  More than half of the the days in September were mostly sunny, while partly cloudy days were most common in October, and mostly cloudy days were most common in November.



Tuesday, September 1, 2020

Summer 2020: Average rainfall but cooler than normal

Meteorological summer consists of June, July, and August.  Summer 2020 in Victoria brought cooler than normal temperatures and normal rainfall.  

The mean temperature this past summer at Victoria Gonzales was 15.3 degrees, which is 0.5 degrees cooler than the 30-year average.  Summer 2020 was the coolest in Victoria since 2012.  All three summer months were about 0.5 degrees cooler than normal.     

The chart below shows the daily maximum and minimum temperatures at Victoria Gonzales during summer 2020, compared with the 30-year averages.  Aside from the occasional short "heat wave", temperatures were generally below average for most of the summer, particularly in early July.  The average high temperature at Victoria Gonzales for summer 2020 was just 19.1 C (17.6 C in June, 19.7 C in July, and 19.9 C in August).  Other locations in the region, away from the cooling effects of the Strait of Juan de Fuca, were warmer.  For example, the average daily high temperature this summer was 20.8 C at Oaklands School, 21.8 C at U-Vic, and 23.3 C at Millstream Elementary in Langford.


Victoria Gonzales averages 38 days each summer when the temperature exceeds 20 C, but for summer 2020 there were only 26 such days: 5 in June, 13 in July (all during the second half of the month), and 8 in August.  There were only 4 days above 25 C in summer 2020 compared with the average of 7.  There were no days when the temperature exceeded 30 C, compared with the average of 1.1 days.  It did exceed 29 C twice: once in late July and again in mid-August.


Daily Max & Min Temperatures in Victoria, Summer 2020



Victoria received 47 mm of rain from June to August, which is exactly normal for the summer period. June was slightly wetter than normal, July was slightly drier, and August was very close to normal rainfall.  

While the amount of rain during summer 2020 was normal, the number of days with measurable rainfall was higher than normal.  Summer 2020 saw 18 days with measurable rainfall (9 in June, 3 in July, and 6 in August) compared with the average of 14.7 days that Victoria usually sees during the summer.  The longest dry spell was 22 days, from July 12 to August 2.  By comparison, the average summer drought period over the past 30 years has been 26 days.


The chart below shows daily precipitation during summer 2020, and compares the cumulative precipitation with the 30-year average.   June and early July started out slightly wetter than normal, but by the end of the summer, total rainfall was right on the 30-year average.  The highest rainfall amount was 7.8 mm on June 9.


Daily & Cumulative Rainfall in Victoria, Summer 2020


The chart below compares the rainfall amounts in Victoria this summer with other locations in the region.  As is typically the case, Victoria Gonzales had the lowest amount, with a total of 47 mm.  The Victoria Airport received 75 mm - nearly 60% more than Victoria Gonzales.  Normal summer rainfall at the Victoria Airport is 67 mm.  Vancouver received 145 mm - more than three times as much as Victoria, which is fairly typical.  Seattle received 97 mm - more than double Victoria's rainfall.  However, most of Seattle's summer rain fell in June, while July and August were actually slightly drier than Victoria.  

Rainfall by location, Summer 2020

Summer 2020 was slightly sunnier than normal.  While June was a bit cloudier than normal, both July and August were sunnier than the long term average, with Victoria receiving around 74% of possible sunshine during those months.

The table below shows the number of mostly sunny days (>80% of possible sunshine), partly cloudy days (20-80% of possible sunshine), and mostly cloudy days (<20% of possible sunshine).  June had only 8 mostly sunny days, compared with the 30-year average of 11.5.  July (19 mostly sunny days) and August (18 mostly sunny days) each had two more sunny days than the 30-year average.