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.

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.