Due to the rain shadow effect of the nearby Olympic Mountains, Victoria is the driest location on the British Columbia coast and one of the driest in the region. Average precipitation amounts in the Greater Victoria area range from at the Gonzales observatory in the City of Victoria to in nearby Langford. The Victoria Airport, north of the city, receives about 45% more precipitation than the city proper. Regional average precipitation amounts range from as low as on the north shore of the Olympic Peninsula to in Port Renfrew just away on the more exposed southwest coast of Vancouver Island. Vancouver measures annually and Seattle is at .