Climate of Vancouver

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The climate of Vancouver, British Columbia is a moderate oceanic climate (Koppen climate classification Cfb) tempered by the warm Japan Current. The city is also sheltered by the mountains of Vancouver Island, to the west. These influences contribute to making Vancouver the second warmest of Canada's major cities.

Contents 1 General weather conditions 2 Temperatures 2.1 Winter 3 Precipitation 3.1 Rain 3.2 Snowfall 4 Other weather information 5 Global Warming 6 Statistics 7 White Christmas 8 Footnotes

[edit] General weather conditions

Its coastal location and mountainous geography make Vancouver a city of microclimates. Local weather variations are sometimes more exaggerated than those experienced in coastal cities like San Francisco. Winter temperatures are usually 2–4°C lower in inland areas, and can be 3–8°C higher during day time, especially in the summer. Predicting precipitation is even more complex. It is a general rule of thumb that for every rise of 100 m in elevation, there is an additional 100 mm of precipitation. Snow, for the aforementioned reasons, has particularly been problematic for meteorologists to predict. For instance, there may be showers in the airport, snow in Queen Elizabeth Park, and rain downtown. Tsawwassen (south of town) is noted to be particularly sunny, while places such as North Vancouver get much more rain.

[edit] Temperatures

[edit] Winter

The coldest month on record for Vancouver International Airport was January 1950, with an average of -6.3C with an average high of -2.9°C and low of -9.7°C.

[edit] Precipitation

[edit] Rain

Although Vancouver is popularly known as a rainy city, only 166 days per year have measurable precipitation on average, and 289 days per year have measurable sunshine. Still, from November until March, it is not uncommon to have 20 consecutive days with some amount of rain. The weather pattern known as the Pineapple Express often brings rainstorms in the winter.

Thunderstorms are rare, with zero to about six^{[citation needed]} occurring through the year, as the Pacific Ocean (and the Strait of Georgia which funnels into the Pacific) does not get warm enough to produce the conditions needed. Sometimes accompanied by hail, they tend to occur more often in fall, winter, and spring than in the summer. Spring and autumn are usually showery and cool.

[edit] Snowfall

Snow occurs in the surrounding mountains and the higher-lying areas such as Coquitlam, Simon Fraser University/Burnaby Mountain, North/West Vancouver, and some of the eastern suburbs, but less often at sea level. There is a general misconception by visitors and residents in other parts of the country that the city does not receive any snow at all, but the truth is there has never been a winter when traceable snow has not been observed at Vancouver International Airport. As a matter of fact, Environment Canada currently ranks Vancouver in 59th place under the category of "Most huge snowfall days (25cm or more)" among 100 major Canadian cities, placing Vancouver above cities such as Calgary (74th place) and Toronto (99th place). ^[1] Snow in Vancouver tends to be quite wet, which combined with typical winter temperatures rising above and falling below 0°C throughout the course of the day can make for unusually slippery road conditions. Rain and sleet are almost interchangeable especially among higher elevations of the city. Years or even months with snowfall surpassing the 100 cm mark are also not completely exceptional; the former occurred twice in the 1990s while January 1972 saw more than 120 cm of snow. Rare November snow storms occurred most recently in 2006, when 30cm to 60cm of snow accumulated across Greater Vancouver and the Lower Mainland in a period of 24 hours. Snow has in fact accumulated at sea level in all months except for June, July and August. However, even small amounts of snow can cause school closures and produce massive traffic problems. Snowfall levels considered routine or mild in other parts of Canada can be relatively catastrophic in Vancouver. Colloquially, this is often said to result from the inexperience of drivers and municipal road crews in dealing with snowfall. Furthermore, the low frequency of snowfall make it hard to justify the public works infrastructure necessary for more effective snow removal as the city is usually in a thaw situation long before plowing of streets are completed. The City budgets $400,000 per year for maintenance of snow removal equipment, for purchasing salt, and for training of staff but costs of actual snow removal are funded separately from contingency reserve funds, and vary widely from season to season. For example, $1.1 million was spent in 1998 compared to $0 in 2001. ^[2] Blizzards are rare but can incapacitate much of the Lower Mainland. One in 1996 resulted in over 60 cm of snow in Vancouver. The system was responsible for millions of dollars in damage.

Snowfall Records for Vancouver International Airport
Snowiest Year: 242.6cm (1971)
Snowiest Month: 121.9cm of snow (January 1971)

• more than 90cm of which fell in a five day period.
• Toronto's snowiest January was 118.4cm in January 1999

Highest Snow Depth: 61cm (January 15, 1971)

Snowfall Records for Other Stations in Vancouver Snowiest Storm: 47cm (January 20, 1935)

[edit] Other weather information

Wind storms are not uncommon in the autumn months. Three wind storms in Vancouver's history knocked down large swathes of trees in Stanley Park's forest. The first was in October 1934, the impact of which was compounded by a blizzard the following January.^[3] The other one was the tail end of Typhoon Freda in 1963 that levelled a six acre tract, which is now the site of the miniature railroad.^[4] Another extra-tropical cyclone swept through the park on 15 December 2006, damaging and uprooting hundreds of trees, caused mudslides, and damaged a section of the seawall.^[5][6]

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 and late sunrises.

Grass-cutting season often begins in February (sometimes even earlier) and continues until October and even November. Summers are often quite dry, and unwatered grass may not need to be cut for over a month. Some summers may have no rain for five weeks or more, others might have several very wet days in a row.

For a few nights near the summer solstice, there are less than 7.5 hours between sunset and sunrise, twilight lasts past 10 PM, and the northern sky remains slightly lit by the sun all night.

In 2010, Vancouver will become the warmest city ever to host a Winter Olympics^[7].

[edit] Global Warming

The effects of greenhouse gases and global warming is evident in Vancouver's climate over the past 50 years, with impact most visible during the winter season. Average monthly maximum and minimum for January has risen from 5.2 and -0.4 degrees Celsius (1941-1970) to the current maximum and minimum of 6.1 and 0.5 degrees Celsius (1971, 2000) - an increase of approximately one degree Celsius. Similarly, average annual snowfall has also dropped from 60 cm to 48 cm. Another factor that could account for at least a portion this change is the increase in heat produced by buildings in the city and surrounding areas, known as the Urban heat island effect.

A number of scientific studies have linked extreme weather patterns to Global Warming [1]

Recently in November of 2006, Vancouver has experienced abnormal levels in rainfall and snowfall,(Vancouver's November rainfall stands at 10.07 inches, a record breaking 7.15 inches above average for the first 16 days of November.) ^[8] Severe windstorms have damaged homes and infrastructure, causing power outages and water contamination affecting 2 million people in the lower mainland. Cafes, restaurants and local and chain businesses have been ordered to stop serving drinks due to the heavy rains washing sediments into Vancouver water reservoirs, (the water from which is used to make coffee, tea and other beverages). With water still declared unsafe, Vancouver embraced yet another weather anomaly: this time in the form of snow. 28cm of snow was recorded at the Vancouver International Airport from the night of November 25 to the morning of November 27 with more than 40cm reported in other areas of the city. Immediately after the snow storm, the temperature dropped to -12.0 degrees Celsius on November 28th, 1.8 degrees higher than the record low for the day set in November 1985 ^[9] (in comparison, the day time high for that day in Toronto was 16.1 degrees Celsius). On November 29th, 10cm more of snow fell on the city. A number of public institutions such as the University of British Columbia and Simon Fraser University as well as colleges and secondary schools were closed entirely. Power outages were widespread across Surrey and Langley. This extreme weather has cost the city, business owners and private citizens an as yet unknown amount in damages. Whether this weather anomaly was a result of global warming is still yet to be determined; however over the course of the past year, all Canadian provinces have experienced highly unusual weather phenomena.

[edit] Statistics

		Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec		Year
Extreme Daily Maximum	°C	15.3	18.4	19.4	25.0	30.4	30.6	31.9	33.3	29.3	23.7	18.4	14.9		33.3
Average Daily Maximum	°C	6.1	8.0	10.1	13.1	16.5	19.2	21.7	21.9	18.7	13.5	9.0	6.2		13.7
Average Daily Minimum	°C	0.5	1.5	3.1	5.3	8.4	11.2	13.2	13.4	10.5	6.6	3.1	0.8		6.5
Extreme Daily Minimum	°C	-17.8	-16.1	-9.4	-3.3	0.6	3.9	6.7	6.1	0.0	-5.9	-14.3	-17.8		-17.8
Average Precipitation	mm	153.6	123.1	114.3	84.0	67.9	54.8	39.6	39.1	53.5	112.6	181.0	175.7		1199.0
Average Total Rainfall	mm	139.1	113.8	111.8	83.5	67.9	54.8	39.6	39.1	53.5	112.5	178.5	160.6		1154.7
Average Total Snowfall	cm	16.6	9.6	2.6	0.4	0	0	0	0	0	0.1	2.5	16.3		48.2
Average Sunshine	h	60	85	134	182	231	229	295	268	199	124	64	56		1928
Data[2] is for Vancouver Airport (YVR), just south of the City of Vancouver

[edit] White Christmas

According to Environment Canada, Vancouver typically has a 13% chance of White Christmas.

[edit] Footnotes

1. ^ Weather Winners WebSite shttp://www.on.ec.gc.ca/weather/winners/element.cfm?lang=e
2. ^ http://vancouver.ca/engsvcs/streets/snow.htm
3. ^ "The Damage in the Park", Vancouver Daily Province, 9 February 1935.
4. ^ Hazlitt, Tom. "It's for real -- this railroad", Vancouver Daily Province, 22 May 1964.
5. ^ Rook, Katie. "Stanley Park ‘looks like a war zone’", National Post, 19 December 2006. Retrieved on December 20, 2006.
6. ^ Kieltyka, Matt. "’Look around, it’s just devastation’", 24 Hours, 18 December 2006. Retrieved on December 20, 2006.
7. ^ "Winter Olympics all wet?: Vancouver has the mildest climate of any Winter Games host city", Vancouver Sun, July 9, 2003.
8. ^ Our Wettest Month Ever http://www.canada.com/vancouversun/news/story.html?id=25b2959c-2679-4b25-95b3-5aa376fa3c1a
9. ^ National Climate Data and Information Archive http://www.climate.weatheroffice.ec.gc.ca/climateData/canada_e.html