It was an off hand and innocuous remark in a Tweet from someone back East after I had posted a sunset photo of Mt. Rainier: "Seattle -- I thought it rained 24/7 there?"
Yes, yes, we get that all the time, right up there with "it rains 9 months of the year there." But it got me to wondering, if not "24/7" -- how often does it really rain in Seattle?
Believe it or not, the data is actually out there to find out.
According to the Western Regional Climate Center, Seattle gets, on average, 822 hours of measurable rain a year, meaning it rains about 9.4% of the time (90.6% dry!!!) That is among the wettest rates on the West Coast, although pales in comparison to the coast where spots like Forks gets 1799 hours (20.5% of the time) and Astoria, Oregon gets 1403(16%).
(On the other hand, Yuma, Ariz. gets a paltry 56 hours or rain a year (0.6%) -- or just a little more than Seattle gets in May alone.)
But to be a true rebuttal to when someone says "it rains here 24/7" let's convert to the same shorthand "hours a day/days a week" fraction: Seattle, on average, gets 155 days with measurable rain a year, meaning it really only rains about 3 days a week [(155/365)*7)] .
And 822 hours of rain falling across 155 rainy days means it rains about 5.3 hours per rainy day on average.
So it doesn't rain in Seattle "24/7" -- it's more like it rains about 5/3!
Breaking down by months:
If you really want to be Seattle weather geeky about it (and who doesn't?) and want to tailor your smart aleck remark to their smart aleck comment: here is how it breaks down by month (rounded to nearest whole number):
January & February: 7/4
July & August: 4/1
November & December: 7/4
See, plenty of dry time! In fact,I guess you could say Seattle is dry 24/4, and 19/3!