Vancouver, Washington - Geography and Climate

Geography and Climate

Vancouver is located at 45°38′1″ North, 122°36′11″ West (45.633743, −122.603011) just north of the Columbia River, just west of where the Columbia River Gorge bisects the volcanic Cascade Range and just east of where the Willamette River enters the Columbia. The city of Vancouver is in the Western Lowlands region of Washington. When clouds do not blanket the Puget-Willamette trough formed by the Cascade and Coast Range, Mount Hood, Mount Saint Helens, Mount Jefferson and Mount Adams are all visible from Vancouver.

According to the United States Census Bureau, the city has a total area of 46.1 square miles (119 km2), of which 7.14% water.

Vancouver lies just north of Portland, Oregon and shares a similar climate. Both are classified as dry-summer subtropical (Csb) on the Köppen climate classification, with certain key exceptions. High pressures east of the Cascade Range create something of a venturi effect, leading to cold east winds down the Columbia River Gorge. Unsheltered by the Willamette Valley, Vancouver has historically seen colder temperatures, including "silver thaw" storms where freezing rain cakes limbs and power lines. Such storms can paralyze Vancouver. They frequently froze the river, and in 1916 cut electric power in the city for almost two weeks. Rainfall occurs frequently throughout the fall, winter, and spring, but ceases around the middle of June, with dry and warm weather lasting through September. Average annual precipitation is 42 inches (1,100 mm). Heavy snowfalls are infrequent and snow often falls and doesn't stick, with major snowstorms only occurring every 2–4 years. Close proximity to the river was also a concern for flooding, before dams constricted the river, destroying features such as Celilo Falls. Periodic floods have been a nuisance, with two of the most destructive in June 1894 and May, 1948. The 1948 Memorial Day flood almost topped the Interstate Bridge's support piers and completely destroyed nearby Vanport, Oregon. Other unusual storms include the Columbus Day windstorm of 1962 and an April 5, 1972 tornado which rated F3 on the Fujita scale, striking a local school. A F1 tornado struck on January 10, 2008 just after noon causing moderate damage along a 2-mile (3.2 km) path from Vancouver Lake to the unincorporated Hazel Dell area.

Because many Vancouver residents work in Portland, there is typically significant rush hour traffic congestion on two bridges that cross the Columbia River — the Interstate Bridge and the Glenn Jackson Bridge. In 2006 there were 278,043 weekday vehicle crossings on the two bridges.