Holiday weather - Canada Day

I thought I would start a series looking at the typical weather in Victoria for various holidays.  First up is Canada - July 1.

While Canada Day doesn't quite fall in the very driest time of year in Victoria (which begins about a week or so later), it is still quite dry.  We actually had a few light sprinkles on Canada Day this year (2016), but there was no measurable rainfall at Victoria Gonzales.  If you look at the full period of record at Gonzales, going back to 1898, there has been measurable precipitation on 14.4% of those years.  More recently, it's been even drier on Canada Day: in the last 22 Canada Days going back to 1995, there has only been measurable rainfall once, when 0.8 mm fell on Canada Day 2010.  That works out to a 4.5% chance.  When it has rained on Canada Day, amounts have generally been light, and the average precipitation for the day (including all those years with no rain) is just 0.3 mm.  The most rain ever recorded on July 1 in Victoria was 8.6 mm in 1933.

Our neighbors to the north in Vancouver don't fare nearly so well when it comes to having a dry Canada Day.  The chance of having measurable rainfall on July 1 in Vancouver is 32% and the average amount of rainfall 3.1 mm - ten times as much as Victoria.  Even if you just look at the 1995-2016 period, which has been so dry on Canada Day in Victoria, it has been much wetter in Vancouver, with measurable rainfall on 8 of those 22 years.

There's a much better chance of having measurable sunshine in Victoria on Canada Day than having measurable rain.  During the period from 1951-1988, there was measurable sunshine on Canada Day 89% of the time.  That's actually quite low compared with other days nearby in the calendar: during that same period, every June 30 had measurable sunshine (100%) while on July 2 there was measurable sunshine 97% of the time.  The average amount of sunshine on Canada Day is 9.3 hours, or about 60% of the 15.6 hours that's possible for that date.

The average high and low temperature for Canada Day at Victoria Gonzales is 19.4/10.8 degrees.  The warmest July 1 was 1942 when the temperature hit a sweltering 33.9 degrees.  The coolest was 1979 when the temperature topped out at a very chilly 13.0 degrees.  The temperature gets above 20 degrees at Victoria Gonzales on only about one third of Canada Days.  It's a different story if you  move inland in the Victoria region: at the University of Victoria, the average temperature on July 1 is 22.9 degrees, and it gets above 20 degrees nearly 80% of the time on Canada Day.

The Year So Far

We've completed six months of 2016, so I thought it would be worthwhile to take a look at the weather in Victoria so far this year.

In terms of temperature, this has been a record warm start to the year.  Last year (2015) was the warmest year on record at Victoria Gonzales, and the first six months of 2015 were also the warmest ever recorded (10.8 degrees).  In 2016, we have beat that record, with a mean temperature of 10.9 degrees for the first six months of the year.  Every month so far in 2016 has been above normal temperatures.  Will we beat 2015 the the whole year record?  Probably not.  July 2016 is so far looking to be much cooler than last July, and with La Nina looming, the end of the year may also be cooler.

The chart below compares daily high and low temperatures with the 30-year averages.  You can clearly see that temperatures have been pretty consistently above average, although we've had a few short stretches of average or slightly below average temperatures in late May and into June.

Daily High and Low Temperatures, January to June 2016

Things are a bit closer to normal when we look at precipitation.  In the first six months of 2016 we have had 261 mm of rain, compared with the normal of 296 mm.  Incredibly, nearly one quarter of the year's rain so far this year fell on a single day - February 15 - when we had a record-breaking deluge of 62 mm.  Without that one day, we would be under 200 mm for the year so far.

The chart below shows daily and cumulative rainfall at Victoria Gonzales for the first six months of 2016.  You can see that we have generally trended below average for most of the year.  You can also see that incredible deluge that we had on February 15.

Daily and Cumulative Rainfall, January to June 2016

Mixed weather in June

After a string of months with warmer and drier than normal weather in Victoria, things were a bit more mixed in June.

The mean temperature for the month was 15.5 degrees, 1.0 degrees above the 30-year average of 14.5 degrees.  The average daily high/low at Victoria Gonzales was 19.7/11.2, again above the average of 18.5/10.4.

The chart below compares the daily high and low temperatures with the averages for June.  The warmest weather of the month was during the first week of June, with temperatures topping out at 30.2 degrees on June 5.  Only about one in five Junes at Victoria Gonzales sees the maximum temperature exceed 30 degrees, so that is relatively uncommon, especially for early June.  The rest of the month was pretty close to average.

Daily High & Low Temperatures at Victoria Gonzales, June 2016

After a dry April and May, precipitation in June was a bit above average, with 26.3 mm compared with the normal 20 mm.  There were 8 days with measurable precipitation in June, slightly above the average of 7 days.  The greatest amount was 9.4 mm that fell on June 15.

While the Victoria Airport typically gets more rain than Gonzales, this June it actually received slightly less - about 24 mm vs. 26 mm at Gonzales.  In Vancouver, there was 58.2 mm at the Airport and 84.1 mm downtown at the Harbour.

The chart below compares daily and cumulative rainfall in June 2016 with the average cumulative rainfall for June.

Daily & Cumulative Rainfall at Victoria Gonzales, June 2016

May was another warm month

After a record warm April in Victoria, our warm streak continued in May.  The mean temperature of 14.1 degrees was just shy of the record (14.2), set back in 2005.  The 30-year normal temperature for May at Victoria Gonzales is 12.3 degrees.  The average daily high/low temperatures this May were 18.3/9.9 compared with the normal of 16.2/8.4.  May was even warmer at the Victoria Airport, with a mean temperature of 14.4 degrees.  This made May 2016 the warmest on record at the Airport, following the warmest April on record.  It's pretty rare to get back-to-back monthly temperature records!  The average daily high/low temperatures at the Airport were 19.7/9.1 - more like June than May.

The chart below compares the daily high and low temperatures this May at Victoria Gonzales compared with the 30-year average.  You can see that temperatures were well above average during the first half of the month.  Temperatures were closer to average in the second half of the month, although there was a spike on May 31.

Daily High & Low Temperatures at Victoria Gonzales, May 2016

May was also dry, with just 10.4 mm of rain in Victoria, compared with the normal of 28.6 mm.  By comparison, there was 12.8 mm of rain at the Victoria Airport, 51.6 mm at the Vancouver Airport, and 76.6 mm at Vancouver Harbour.

The chart below shows daily and cumulative rainfall (red line) compared with the average cumulative rainfall (blue line) at Victoria Gonzales for May 2016.  Clearly, it was much drier than average.  Nearly three quarters of the month's rainfall fell on one day - May 28.

Daily and Cumulative Rainfall at Victoria Gonzales, May 2016

With the mild temperatures in March, followed by record or near record temperatures in April and May, Spring 2016 was the warmest on record at both Victoria Gonzales and at the Airport.  At Gonzales the mean temperature was 11.9 degrees compared with the average of 10.1.  Average high/low temperatures at Victoria Gonzales were 15.4/8.3 compared with the normal spring high/low of   13.5/6.5.

How long will this string of warmer than average temperatures last?  Perhaps not much longer since El Nino is now dead and there is a La Nina on the horizon.

A record-breaking April

Our streak of warmer than average months continued in a big way in April - it was the warmest April on record in Victoria.  The mean temperature at Victoria Gonzales was 12.4 degrees, easily beating the old record of 12.1 degrees set back in April 2004, and well above the 30-year average of 9.9 degrees.  The temperatures this April were more like May - in fact the mean temperature equaled the 30-year average for May.  The average daily maximum and minimum temperatures were 15.9/8.8 vs. the April normal 13.4/6.3.   The warmest temperature was 25.5 degrees on April 20 (close to the all time April maximum of 27.0).  The coolest temperature was 7.1 degrees on April 9.  That is the warmest extreme monthly minimum ever recorded for April.

The chart below compares the daily maximum and minimum temperatures for April with the 30-year average temperatures.  Maximum temperatures cycled between being close to average and being well above average.  The overnight minimum temperatures were consistently above average.

Daily maximum and minimum temperatures, April 2016

The warmth wasn't limited to Victoria Gonzales.  April 2016 was also the warmest on record at the Victoria Airport, as well as in Vancouver, Seattle, and Portland.

April was also much drier than normal, with just 8.8 mm of rain at Victoria Gonzales, compared with the 30-year average of 31.5 mm.  There was measurable rainfall on 7 days in April compared with the normal of 11 days.

The chart below shows the daily and cumulative rainfall at Victoria Gonzales for April 2016.  Clearly, it was much drier than normal.

Daily and cumulative precipitation, April 2016

It was generally dry throughout the region in April, although, as is typical, other areas did get more rain than Victoria.  The chart below compares April rainfall totals.  Compared with 8.8 mm at Victoria Gonzales, amounts at the Victoria Airport were quite similar (10.4 mm).  Somewhat higher amounts were recorded at Saltspring Island (24.1 mm), Vancouver Harbour (26.3 mm) and Seattle Airport (30.2 mm).

The Mild Streak Continues in March

I'm a little late, but I'm finally getting around to looking back at last month's weather!

The mild streak continued in March, with a mean temperature of 9.1 degrees, compared with a 30-year March average of 7.8.  That's warm enough to make it into the top 10 warmest Marches in the past 118 years at Victoria Gonzales.  The average daily maximum and minimum this March were 11.9 and 6.2, compared with the  normal 11.0 and 4.8.  The warmest temperature was 18.0 on the 30th and the coolest was 3.2 on the 16th.

The chart below compares the daily maximum and minimum temperatures this month with the 30-year averages.  You can see that temperatures were generally above average, particularly at the end of the month.  The daily minimum temperature was above average for 23 of 31 days in March.

March 2016 Temperatures in Victoria

March 2016 was quite close to average in terms of precipitation, with 56 mm compared with the average of 50 mm.  The chart below compares the daily and cumulative precipitation for the month with the average cumulative precipitation.  You can see that the month started out quite wet, and by mid-month we were were at almost double our normal precipitation.  However, the second half of the month was dry so were were only slightly above normal by the end of the month.  There was measurable precipitation on 16 days, slightly more than the normal of 15 days.  The wettest day was the 9th, with 15 mm of rain.

March 2016 Daily Precipitation

The chart below compares Victoria's total precipitation in March 2016 with some nearby locations.  As is typical, Victoria was a lot drier.  Compared with Victoria (as measured at the Gonzales weather site),  the Victoria Airport had just over double the rainfall - 119 mm vs 56 mm.  Nanaimo was particularly wet this March, with 247 mm - more than four times as much rain as Victoria. Vancouver, with 198 mm had almost four times as much rain while Seattle, with 140 mm, had about 2.5 times as much rain as Victoria.

March was also another month with no snow in Victoria, which also means another winter with no snow.  We have now had four winters in a row with no snow.  The last time Victoria saw snow accumulate on the ground (more than 1 cm) was January 2012.

Which has a better climate - Victoria or Toronto?

Our climate smackdown series continues.  Next we'll compare Victoria's climate to Toronto's.  All the numbers below are based on stats for Victoria Gonzales and for Toronto City (not Airport numbers).  

Let's start with precipitation.  On an annual basis, Toronto gets about 30%  more precipitation than Victoria - 831 mm in Toronto versus 641 mm in Victoria.    If you split that into rain and snow, Toronto gets about 20% more rain than Victoria (741 mm vs. 621 mm) and about 6 times as much snow (122 cm vs. 20 cm).  

Besides getting more precipitation, Toronto also differs from Victoria in the seasonal pattern of its precipitation.  While Victoria has a very distinct rainy season (late fall and winter) and dry season (late spring and summer), precipitation in Toronto is more or less the same year round.  You can see the difference in the chart below.  Victoria gets about 50% more precipitation than Toronto in November, December, and January (318 mm vs. 207 mm).  Precipitation levels are about the same in both cities during the transitional months of February and March, and again in October. During the six months from April to September, Victoria gets less than one third as much rain as Toronto (137 mm vs. 451 mm).  The difference is particularly pronounced during June, July, and August when Victoria gets less than one quarter as much rain as Toronto.  One of the big reasons for the much drier summers is the lack of thunderstorms in Victoria: Toronto averages about 28 days annually with thunderstorms compared with about one day in Victoria.

We can also compare the frequency of precipitation.  For example, Victoria averages 133 days per year with measurable precipitation versus 145 days in Toronto. The chart below compares the % chance of measurable precipitation on any given day throughout the year.  Again, you can see there is much more seasonal variation in Victoria, ranging from 60% chance during November and December to a 10% chance in late July and early August.  The likelihood of precipitation has a much smaller seasonal range in Toronto, from about 50% in the winter down to about 30% in late summer.  The chance of having a day with measurable rainfall is lower in Victoria from early April until early October.  The gap is especially wide from mid-July until mid-August: if you're planning an outdoor event at this time of year it's about three times as likely to get rained out in Toronto compared with Victoria. 

As noted earlier, Toronto gets more than 6 times as much snow as Victoria, with an average 122 cm annually in Toronto versus 20 cm in Victoria.  Snow also stays on the ground much longer in Toronto, with an average of 68 days each winter with at least 1 cm of snow on the ground compared with 5 days for Victoria.  Although on average, Victoria gets much less snow, it has had more really large snowfalls than Toronto.  The biggest one-day snowfall in Toronto in the past 100 years was 48 cm in December 1943.  In Victoria, there have been three one-day snowfalls that exceeded 50 cm, in February 1916, February 1923, and December 1996.  

Victoria is also sunnier than Toronto, with an average 2,203 hours of sunshine annually versus 2,066 hours for Toronto.  Victoria averages 315 days per year with at least some measurable sunshine, leaving an average 50 days per year with no sun.  Toronto averages 60 days annually with no measurable sunshine.  The chart below shows the % of possible sunshine, by month, throughout the year.  Victoria gets a slightly lower percentage of possible sunshine than Toronto during the winter, from December until March.  However, from April to October Victoria gets a higher percentage of possible sunshine.  The difference is especially noticeable in July and August, when it's sunny nearly 70% of the time in Victoria compared with about 58% in Toronto. 

Now let's compare temperature.  While Victoria has  much greater seasonal variation in precipitation and sunshine compared with Toronto, the opposite is true for temperature.  The chart below shows the average daily maximum temperature in Victoria versus Toronto.   Average maximum temperatures in Victoria range from 7 degrees in December to 21 degrees in July - a difference of about 14 degrees.   In contrast, maximum temperatures in Toronto range from -2 degrees in January to 27 degrees in July - a range of 29 degrees, or more than twice the range experienced in Victoria.  The average daily maximum temperature is warmer in Victoria for half the year, from mid-April to mid-October.  The greatest difference is in mid-January, when the average daily maximum is nearly 10 degrees warmer in Victoria compared with Toronto.  In contrast, in July the average daily maximum temperature is 6 degrees cooler in Victoria compared with Toronto.  (It should be noted that the numbers for Victoria are based on Victoria Gonzales, located right on the Strait of Juan de Fuca.  Away from the Strait, at the University of Victoria, the average high temperature in July is 23.8 degrees, nearly 3 degrees warmer than Gonzales).  

The next chart shows average daily overnight low temperatures in Victoria versus Toronto.  The pattern is very similar to the daily high temperatures discussed above: there is a much greater seasonal range in Toronto, with average overnight lows ranging from -8 degrees in January to nearly 19 degrees in July (a 27 degree range).  In Victoria, overnight lows range from 3 degrees in December to 12 degrees in August (a 9 degree range, only one third of the range in Toronto).  Average overnight lows in Victoria exceed those in Toronto for an even longer period than the daytime highs do, from early October to early May.  In Toronto, average overnight lows are below 0 from the beginning of December to the end of March, and Toronto averages 101 days per year with overnight lows below freezing.  Victoria averages less than 10 such "frost days" per year.  

The coldest temperature ever recorded in Victoria was -15.6 degrees in December 1968.  On the other hand, Victoria has experienced 7 winters in the past 118 years when the temperature did not drop below freezing.  The coldest temperature recorded during the winter of 1925-26 was +1.1 degrees, making it the highest low temperature for any winter on record.  In Toronto, the lowest temperature ever recorded was -32.8 degrees.  The highest low temperature for any winter in Toronto was -13.1 degrees during the winter of 2005/06.  In Victoria, the average coldest temperature each winter is -4.8 degrees, while the average winter low temperature for Toronto is -20 degrees.  

The record maximum  temperature for Victoria is 36.0 degrees versus 40.6 degrees for Toronto.  Toronto gets an average of 50 days per year above 25 degrees and 13 days above 30 degrees.  In contrast, Victoria gets an average of just 8 days per year above 25 degrees and 1 day per year above 30 degrees.  Again, if you measure the temperature away from the Strait of Juan de Fuca (at the University of Victoria), it's more like 27 days above 25 degrees and 3 days above 30 degrees.  Either way, Victoria's summers are much cooler than Toronto's - and no humidity!

So who wins the climate smackdown?  I think it's pretty clear that Victoria wins in terms of more sunshine, less rain, and much less snow.  It also wins for having much milder winters.  However, the summer temperatures are more subjective.  Being a Victoria native, I love the cool summers here, but I know that some people prefer the heat in the summer.  Give me cool, dry and sunny over hot and muggy any day, although it would be nice to have a few more warmer summer evenings in Victoria!  Overall, I still have to give this one to Victoria.