Hi Jim: Wish I could help. I'd like similar information for my area too. Particularly interested in knowing how much weekly rainfall in my backyard. (I know ... I know ... get a rain gauge and keep a journal.) TV weathermen get all sweaty and foamy at the mouth at the prospect of reporting a broken temp record (who likes extreme weather anyway?) but don't give much useful information. Given gardening is the most popular pastime in US (depending on whose survey you believe), you'd think they'd jump on that niche in the rating wars. Recently saw a report on the sunniest, wettest, cloudiest cities in US but that isn't what you are looking for.

NOAA has probably the best historical weather records for any given location but you will have to request them specifically (and prepay).

The San Juans are considered part of the "banana belt" and fall within the same rain shadow that Sequim does. The same geological conditions that result in low rainfall in this area also result in more clear days. You can find reports for Eastsound that indicate it receives on average 247 clear days annually and less than 30 inches of precipitation.

Here is a link that might be useful: NOAA weather data