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San Juan Island's Rain Shadow

The Pacific Northwest is known for its rainfall.  And we are not complaining.  The rainfall here means full rivers, green grass, and a wonderful temperate summer.   While places like the Olympic Peninsula get up to 60 inches of rain a year and Seattle close to 40 inches, San Juan Island receives as little as 15 inches of annual rain fall.  Why the difference?  San Juan Island is in a rain shadow, which acts as a kind of umbrella for the islands.  Here in the San Juans we are surrounded by mountains.  With the Cascades to the east, the Olympic Peninsula to the south, and Vancouver Island to the west, San Juan is protected from many storms.  Rain clouds are low and heavy, making it easy for them to get "stuck" on the surrounding mountains.  This phenomenon makes San Juan Island relatively dry in the winter.  There are plenty of gray days, and this year plenty of sunny ones too, here on San Juan Island, but it can be an escape for the down pours of the surrounding areas.

With a mild winter and an amazing summer, San Juan Island is a wonderful place to visit and call home.

Naturalist Emily

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