Vancouver British Columbia has a moderate oceanic climate (Koppen climate classification Cfb) with summer months that are typically dry, often resulting in moderate drought conditions, usually in July and August. In contrast, the rest of the year is rainy, especially between October and March.
The city is tempered by the warm Japan Current and is also sheltered by the mountains of Vancouver Island, to the west. These influences contribute to making Vancouver the second warmest (after Victoria) of Canada’s major cities overall, despite the fact summers are cooler than most other major cities.
General Conditions
The climatology of Vancouver applies to the entire Greater Vancouver region and not just to the city of Vancouver itself. While Vancouver’s coastal location serves to moderate its temperatures, sea breezes and mountainous terrain make Greater Vancouver a region of microclimates, with local variations in weather sometimes being more exaggerated than those experienced in other coastal areas.
Predicting precipitation in the Greater Vancouver area is particularly complex. It is a general rule of thumb that for every rise of 100 metres in elevation, there is an additional 100 millimetres (1.2 in per 100 ft) of precipitation, so places such as North Vancouver on the North Shore Mountains get more rain. Snow has been particularly problematic for meteorologists to predict due to variations in elevation and the moderating effect of the coast on temperatures.
Temperatures
The annual average temperature in Vancouver is 10.1 °C (50.2 °F), amongst the mildest in Canada. It is located in a USDA plant hardiness zone of 8, similar to Seattle, Portland, Amsterdam and London, as well as places such as Atlanta, Georgia and Raleigh, North Carolina, far to the south. The warm Japanese current usually keeps winter temperatures mild, especially along the lower-lying coastal areas.
Despite normally mild winters, some winters see the arrival of cold arctic outflows from the interior of the continent that can sometimes last a week or more. The coldest month on record at Vancouver International Airport was January 1950, with an average low of −9.7 °C (15 °F) and an average high of −2.9 °C (27 °F), making for a daily average of −6.3 °C (20.7 °F). In 2010, Vancouver became the warmest city to date to host the Winter Olympics.
The Metro Vancouver region is also subject to significant variations in summer temperatures, which can change by as much as 5-10 °C between inland areas of the Fraser Valley and the ocean-tempered coastal regions. Conversely, winter temperatures tend to be cooler inland.
Daylight
Winters in Vancouver can be dark, as the sky during this time is often covered with low-altitude grey clouds, and the relatively high latitude means early sunsets (as early as 4:15 pm) and late sunrises (as late as 8:05 am).
Summers, in contrast, are characterized by a nearly opposite weather pattern, with consistent high pressure and sunshine. July and August are the sunniest months. For several nights near the summer solstice, there are fewer than 7.5 hours between sunset and sunrise, with twilight lasting past 10 pm and the northern sky slightly lit by the sun all night.
Although popularly thought of as being a rainy city, Vancouver has only 166 days per year with measurable precipitation on average, and 289 days with measurable sunshine. Nonetheless, from November until March, it is not uncommon for there to be 20 consecutive days with some amount of rain. The weather pattern known as the Pineapple Express often brings warm rainstorms in the winter.
Thunderstorms are rare, with an average of 6.1 thunderstorm days per year.[5] The weather in spring and autumn is usually showery and cool.
Grass-cutting season often begins in February and continues through October. Summers can be quite dry, and, as such, unwatered grass may not need to be cut for a month or even longer. Some summers may have no rain for five weeks or more, while others might have several very wet days in a row.
