Weather Blog

Could be first sunny weekend since August!

Could be first sunny weekend since August!
Around here, sunshine and weekends usually go together like peanut butter and oysters, but this weekend, sunshine has found a home. In fact, it is shaping up to be the first official sunny weekend in Seattle since Aug. 1-2!* (* -- we were really close on Dec. 26/27, with 27th rating a '4' in cloud cover, which is one point over sunny. An official sunny day is 0-3 tenths cloud cover, partly sunny is 4-7 and cloudy is 8-10. The 26th was a 0, meaning totally clear.)

The temperature that weekend in August? 90 and 89 (coming off that massive end-of-July heat wave). So this should be a bit more comfortable.

It's also way overdue -- did you know the "best" day in January rated a '7' on the cloudy scale?

We might rate official sunny days through Monday, giving us a string of six in a row. We didn't even get that last summer as occasional marine layer days stopped the streak (We did have two separate five-day streaks). In fact, it could be the longest sunny streak since a 9-day streak in Sept. 8-16, 2008(!).

How do they get those daily "ratings" for sunshine? I believe what happens is there is a sensor that measures how many minutes it receives sunshine, and then it divides by the number of minutes between sunrise/sunset each day to get a percentage. So if there's sun for 82% of the day, it rates a "2". (That's because I guess it's measured backwards -- how many minutes it's *not* sensing sun, which is why 10 is overcast.)

But fog and the like counts as no sun, and thus in such a heavy marine climate, even what locals would consider a pretty nice, sunny day might officially rate a 4 or 5 due to morning clouds and/or fog. So a true sunny streak is hard to maintain.

You can find these stats here: Click on the "Preliminary Monthly Climate Report (CF6)" Button, then set the city and month/date you want. It'll pop open a window with that month's data. The sun rating is under "S-S" Column and it's a number from 0-10. At the bottom, totals them up.

Anyway, the ol' familiar rainy pattern returns late Tuesday with showers moving in late in the day. Rain remains in the forecast at times each day through the rest of the week, meaning seafood restaurants can probably hold off on that big order of Jif :)