Why is the coast so windy in summer?
Marty Giles, a naturalist who runs Wavecrest Discoveries, often has to explain the phenomenon to guests of her tour business.
In the summer, the waters of the North Pacific are cooler than the land. Above these cool waters is a mass of cool, high-pressure air called the North Pacific High.
"Since winds around high pressure systems in the Northern Hemisphere rotate in a clockwise direction, our eastern edge of the Pacific gets the north-to-south part of the wind gyre -- cold summer winds," Giles explained.
In winter, the land is cooler than the North Pacific waters, and the air above the North Pacific rises, creating a low-pressure system off our shore. "Winds around low-pressure systems in the Northern Hemisphere rotate in a counter-clockwise direction, bringing warm moist air from the south to our wintry shore."
When this warm, moist air encounters the colder air over the land, it drops its moisture as our abundant winter rain.
In addition to this large-scale air movement, on a sunny summer day, as warm air rises off the land, cool ocean air flows toward the land to take its place. The hotter the sun, the faster the ocean air rushes toward the land.
Winds are lowest when the temperatures of land and water are closest, so head for the beach or paddle a coastal lake in the morning. The closer temperatures between land and water in autumn also give September our best weather.