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 rule of thumb that for every rise of in elevation, there is an additional ( per ) of precipitation, so places such as the
District of North Vancouver on the
North Shore Mountains get more rain.
Snow is problematic for
meteorologists to predict due to temperatures remaining close to freezing during snow events.
Temperatures trees in Vancouver. Some subtropical plants can survive high west coast latitudes in oceanic climates. The average annual temperature in Vancouver is downtown and at
Vancouver International Airport in
Richmond. This is one of the warmest in Canada. Greater Vancouver is in
USDA plant hardiness zone 8, similar to other coastal or near-coastal cities such as
Seattle,
Portland,
Amsterdam, and
London, as well as places such as
Dallas, Texas and
Raleigh, North Carolina, far to the south (however, these locations have far more growing degree days due to their hot summers). The semi-mild climate sustains plants such as the
Windmill Palm, know to be the hardiest palm tree in the world. Vancouver's
growing season averages 221 days, from March 29 until November 5. This is 72 days longer than
Toronto's, and longer than any other major urban centre in Canada. Despite normally semi-mild winters (for its latitude) due to the onshore air flow over the North Pacific Current, occasional cold
squamish or Arctic outflow (sinking cold continental air that flows down through the
Fraser Valley coastward) in winter can sometimes last a week or more. These Arctic outflows occur on average one to three times per winter. The coldest month on record at
Vancouver International Airport was January 1950 when an Arctic air inflow moved in from the Fraser Valley and remained locked over the city, with an average low of and an average high of only , making for a daily average of , colder than normal. The coldest temperature ever recorded in the city was on December 29, 1968. The coldest temperature across
Metro Vancouver, however, is recorded in
Pitt Meadows on January 23, 1969. With snow being an infrequent occurrence over a typically cool to mild winter, many cold hardy flowers remain in bloom and are common in gardens and office exteriors throughout the winter. The arrival of spring is often first noticed in late February with slightly milder temperatures and the return of flowering perennials. It is also not uncommon for cherry trees to begin blooming later in the month, as was seen prominently during the
2010 Winter Olympics. However, in some years there is also snowstorms and cold temperatures. The Greater Vancouver region is also subject to significant variations in summer temperatures, which can differ by as much as between inland areas of the Fraser Valley and the ocean-tempered coastal regions when localized on-shore breezes are in effect. Conversely, winter temperatures tend to be cooler inland by a couple of degrees.
Daylight The relatively high
latitude of 49° 15′ 0″ N (similar to
Paris, France, at 48° 85′ 66″) means
sunsets as early as 4:10 pm and
sunrises as late as 8:12 am. From November to February, at the sunshine measuring station at the airport in Richmond, on average more than 70% of the already short daytime is completely cloudy. The percentage of cloudiness is higher in Vancouver and especially the
North Shore because upslope winds going up the mountainsides lead to the development of clouds. In a typical winter, Vancouver averages less sunshine than any other major city in Canada. While fleeting, summers, in contrast, are characterized by a nearly opposite weather pattern, with consistent high pressure and sunshine. July and August are the sunniest months. Near the summer
solstice, there are less than 8 hours between sunset and sunrise, which in combination with most of British Columbia observing
daylight savings time means that
civil twilight can last past 10 pm. ==Precipitation==