Which has a better climate - Victoria or Calgary

Our climate smackdown series continues.  We have already compared Victoria's climate with Vancouver and Toronto.  This time we'll look at Calgary.  

Let's start with precipitation.  On an annual basis, Calgary gets about 35%  less precipitation than Victoria - 419 mm in Calgary versus 641 mm in Victoria.    If you split that into rain and snow, Calgary gets barely half as much rain as Victoria (326 mm vs. 621 mm) but Calgary gets about six and a half times as much snow (129 cm vs. 20 cm).  

Calgary also greatly differs from Victoria in the seasonal pattern of its precipitation.  Victoria gets most of its rain in late fall and winter, while the late spring and summer is very dry.  In Calgary, the precipitation pattern is the opposite of this, with a very dry late fall and winter, but a decidedly wet late spring and summer.  You can see the difference in the chart below.  The driest six months in Victoria occur during the growing season, from April to September, with a total of just 137 mm, or 21% of the annual total during that period.  By contrast, April to September are the wettest six months of the year in Calgary, with 344 mm or about 82% of the annual total (and two and half times as much rain as Victoria gets during the growing season).   During Victoria's wettest months, in November, December, and January, it gets about ten times as much precipitation as Calgary, but during the dry summer months of June, July, and August, Calgary gets four to five times as much rain as Victoria.  While Victoria gets more annual precipitation than Calgary, Victoria, on average, is drier than Calgary during five months; May, June, July, August, and September,  One of the big reasons for the much drier summers in Victoria is the lack of thunderstorms: Calgary averages about 27 days annually with thunderstorms - nearly all between May and August - compared with about one day per year in Victoria.

We can also compare the frequency of precipitation.  For example, Victoria averages 133 days per year with measurable precipitation versus 112 days in Calgary. The chart below compares the % chance of measurable precipitation on any given day throughout the year.  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 smaller seasonal range in Calgary, from about 20% in November and December up to about 45% in June.  The chance of having a day with measurable rainfall is lower in Victoria from late April until mid-September.  From late-July until mid-August, Calgary is more than three times as likely as Victoria to get a rainy day.  During November and December, the reverse is true, with Victoria about three times as likely to get a day with precipitation compared with Calgary.

As noted earlier, Calgary gets more than 6 times as much snow as Victoria, with an average 129 cm annually in Calgary versus 20 cm in Victoria.  Snow also stays on the ground much longer in Calgary, with an average of 86 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 Calgary.  The biggest one-day snowfall in  Calgary in the past 100 years was 48 cm in May 1981.  In Victoria, there have been three one-day snowfalls that exceeded 50 cm, in February 1916, February 1923, and December 1996.  

Calgary does beat Victoria in terms of sunshine, with an average 2,396 hours of sunshine annually, nearly 9% more sunshine than Victoria's 2,203 hours.  Victoria averages 315 days per year with at least some measurable sunshine; Calgary gets 333 such days.  Looking at the flip side, Victoria averages 50 days each year with no measurable sunshine while Calgary averages just 32 such days.  While Calgary gets more sunshine than Victoria on an annual basis, there are some important seasonal variations, as was the case with precipitation.  The chart below shows the % of possible sunshine, by month, throughout the year.  Victoria gets a much lower percentage of possible sunshine than Calgary during the winter months.  In December, for example, Victoria gets just 26% of possible sunshine hours while Calgary gets 46%.  However, from May through September Victoria gets a higher percentage of possible sunshine than Calgary.  Victoria's summer sunshine advantage peaks in July,  when it's sunny 69% of the time in Victoria compared with about 63% in Calgary. 

Now let's compare temperature.  Calgary, of course, has much colder winters, and it also has a  much greater seasonal variation in temperature compared with Victoria.  The chart below shows the average daily maximum temperature in Victoria versus Calgary.   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 Calgary range from -4 degrees in January to 25 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 from the beginning of September until mid-May.  The greatest difference is in  late January, when the average daily maximum is nearly 12 degrees warmer in Victoria compared with Calgary.  In contrast, in July the average daily maximum temperature is 3.5 degrees cooler in Victoria compared with Calgary.  (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 and about the same as Calgary).  

The record maximum  temperature for Victoria is 36.0 degrees versus 36.1 degrees for Calgary.  Calgary gets an average of 87 days per year above 20 degrees and 5 days above 30 degrees.  In contrast, Victoria gets an average of just 50 days per year above 20 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 95 days above 20 degrees and 3 days above 30 degrees.  

The next chart shows average daily overnight low temperatures in Victoria versus Calgary.  Compared with Victoria, average overnight lows are cooler in Calgary throughout the year.  However, there is a much greater seasonal variation in Calgary, so there is a much greater difference between Victoria and Calgary in the winter.  Overnight temperatures range from about 3 degrees cooler than Victoria in the summer down to nearly 20 degrees colder than Victoria in the winter.  In Calgary, average overnight lows are below 0 from the mid-October until the end of April, and Calgary averages a whopping 194 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 Calgary, the lowest temperature ever recorded was -45 degrees.  The highest low temperature for any winter in Calgary was -22 degrees during the winter of 1986/87.  In Victoria, the average coldest temperature each winter is -4.8 degrees, while the average winter low temperature for Calgary is -34 degrees.  

So who wins the climate smackdown?  I think Victoria clearly wins in terms of temperatures.  While summer high temperatures are a little cooler in Victoria (at least near the water), Calgary is much colder in the winter, and overnight temperatures are colder in Calgary throughout the year.  On an annual basis, Calgary is drier and sunnier than Victoria (although Calgary gets much more snow).  However, during the warmer late-spring and summer months, Victoria actually gets less rain and more sunshine than Calgary.  While Victoria is much wetter and cloudier during the winter months compared with Calgary, it is also much warmer.  While the definition of best climate is subjective, I think Victoria wins this showdown: it has a sunnier, drier summer than Calgary and, in my opinion, a cloudier and wetter winter is a worthwhile trade-off for Victoria's much milder winter temperatures, 

Victoria's advantage when the weather is unsettled

We're currently into a perfect stretch of warm, dry and sunny summer weather: take a look at the forecast for Victoria for the next week.

However, it seems like earlier in the summer the weather was a bit more unsettled than usual, especially in June and the first half of July.  While we might complain when the weather's not perfect in the summer, we should remember that compared with other locations in the region, Victoria's weather actually stands out the most when the weather pattern is a bit more unsettled.  When we have a strong ridge of high pressure giving us the sunny weather we're currently experiencing, other parts of the B.C. south coast are usually experiencing similar conditions.  It's when the weather's unsettled that Victoria's climate really shines.  Unsettled weather during the summer might mean a little more cloud and a chance of sprinkles in Victoria, while in other parts of the region they are getting much more cloud and rain.

Let's start by comparing the rainfall in Victoria and Vancouver this summer.  The chart below compares monthly rainfall from May up until today (August 14) at Victoria Gonzales and Vancouver Harbour (downtown).  You can see that Vancouver has clearly had a LOT more rain.

Summer 2016 Monthly Rainfall, Victoria vs. Vancouver

On average, Vancouver gets about three times as much rainfall from May to August than Victoria (240 mm vs. 80 mm).  This year, Vancouver has had five times as much rain as Victoria (224 mm vs 45 mm).

The chart below compares the total May-August 2016 rainfall (up to August 14) at Victoria Gonzales with several other  locations in the region.  Although the Victoria Airport usually gets about 35-40% more rain than Victoria Gonzales during the summer, this year it's been almost as dry.  However, Vancouver Airport (located in a relatively dry part of the Vancouver region) has had more than three times as much rain as Victoria, and as we've seen, Vancouver Harbour has seen five times as much rain.  Nanaimo, Comox, and Campbell River - which normally get about twice as much rain as Victoria during the summer - have received nearly three times as much rain as Victoria this summer. Finally, Seattle Airport - which normally gets about 60% more rain than Victoria during the summer - has received about double Victoria's rainfall this summer.

Total Rainfall, May to August 2016

So during this somewhat unsettled summer, other locations in the region have received even more rain relative to Victoria than they normally do.  We might grumble sometimes when we get a patch of unsettled weather in the summer instead of the endless sunny days that we expect, but we should keep in mind that when it's unsettled here in Victoria, it's probably still a lot better weather than other parts of the region.

While we're talking about the rainfall amounts this summer, I'd just like to comment on another case of it all being relative.  We've heard in the news that Southern Ontario is experiencing a severe drought this summer.  In Toronto, they have received just 45% of their normal rainfall since the beginning of May.  Sounds pretty dry, doesn't it?  The thing is, normal May-August rainfall in Toronto is 300 mm, so 45% of that is 135 mm - or about three times as much rain as Victoria has seen over the same period.  For Victoria, 135 mm of rain during May to August would be an unusually wet summer, and certainly wouldn't be considered a severe drought!  In fact, in 117 years of record-keeping at Victoria Gonzales, there have only been five summers where our rainfall totals have reached 135 mm.  As I said, it's all relative!

BC Day - the most reliable weather of the year in Victoria

I'm continuing my look at average weather on major holidays in Victoria.  We last looked at Canada Day - next up is BC Day.

BC Day doesn't fall on a specific day - it is the first Monday in August.  That means, it can fall anywhere from August 1 to 7.  For the purposes of this discussion, I will use the weather averages for August 1-7.  This period is right in the middle of the driest, sunniest, and warmest time of year in Victoria (which generally extends from mid-July to mid-August).  

Looking at the 1981-2010 period, there is just a 9.1% chance of measurable rain on BC Day.  By comparison, the chance of rain is 14.4% on Canada and 20.0% on Labor Day, so the BC Day long weekend is definitely the most reliable for camping or other outdoor activities.  In fact, Victoria's weather on BC Day is more reliably dry than any other city in Canada.  The chance of measurable rain on BC Day is nearly twice as high in Vancouver (16.7%), and nearly four times as high in Calgary (33.2%) and Toronto (33.3%).

BC Day is also generally the sunniest holiday in Victoria.  There is a 97.3% chance of getting measurable sunshine on BC Day in Victoria.  On average Victoria gets 10.5 hours of sunshine on BC Day, meaning that it is sunny about 72% of daylight hours.  That compares with 9.3 hours (60% of possible) on Canada Day.  While that's impressive, BC Day actually just misses the sunniest time of year in Victoria: during the last 10 days of July there is an average of 12.1 daily hours of sun, meaning it is sunny 81% of daylight hours during this period.  Again, Victoria is more reliably sunny on BC Day than other major cities across Canada.  While Victoria gets 72% of possible sunshine on BC Day, Vancouver and Calgary both average 63% and Toronto averages 58%.  Even Penticton in the "sunny Okanagan" averages just 62% of possible sunshine on BC Day.

The average high and low temperature for BC Day at Victoria Gonzales is 20.6/11.9 degrees, making it the warmest holiday of the year.  The warmest it's been during the first week of August is 32.8 degrees on August 6, 1942 (which was also the year Victoria had its hottest Canada Day on record).  The temperature gets above 20 degrees about half the time during the first week in August at Victoria Gonzales.  It's a different story if you  move inland in the Victoria region: at the University of Victoria, the average temperature during the first week in August is 24.0 degrees, and it gets above 20 degrees nearly 90% of the time during the first week in August, and above 25 degrees nearly 40% of the time.

A fairly typical July

This past July turned out to be pretty typical in Victoria.

The mean temperature for the month was 16.1 degrees, which is right on the 30-year average.  If you go to 2 decimal points, the mean temperature was 16.10 versus the average of 16.07, so we did continue our streak of above average temperatures, albeit by a very small margin!  Since the beginning of 2014, 28 of the past 31 months have been warmer than the long term average.

I was a little surprised when I saw the stats for July, because it seemed to me like it was a little cooler than normal.  That may be because, while the mean temperature was bang on normal, the average daily high temperature was a little below normal (20.1 versus 20.4) while the average daily low temperature was slightly above normal (12.1 versus 11.7).  In addition, we didn't get any really hot weather during July, at least at Victoria Gonzales.  The warmest temperature this month at Gonzales was 23.1 degrees on July 21.  On average, the warmest temperature during July is usually around 28 degrees.  Victoria Airport also saw close to average temperatures in July, although the highest temperature for the month was a warmer 27.0 degrees, also on July 21.

The chart below compares the daily high and low temperatures with the averages for July.  You can see that the temperatures stayed very close to average throughout the month, with no big swings above or below the averages.

Daily Max and Min temperatures, July 2016

July was drier than average, with 8.0 mm of rain at Victoria Gonzales compared with the normal of 12.6 mm.  However, that's not an unusually low amount for Victoria -  there's been less than 8 mm of rain during more than 4 in 10 July's over the past 100 years.  There were five days with measurable precipitation in July, which is pretty typical for Victoria.  The wettest day was July 7th, with 2.8 mm of rain.

As is typical, Victoria Gonzales received less rain in July than other locations in the region.  Compared with 8 mm at Gonzales, the Victoria Airport received 13.6 mm.  In Vancouver, there was 32.8 mm at the Airport and 59.2 mm downtown at the Harbour.  The Seattle Airport received 18.3 mm.  In Nanaimo, there was 34.0 mm of rain

The chart below compares daily and cumulative rainfall in July 2016 with the average cumulative rainfall for July.  While we ended up the month with a little less rain than average, it was actually quite typical.

Daily and Cumulative Rainfall, July 2016