After a dreary few days with chilly daytime temperatures, a big warmup is on the way for Western Washington!
We’ll start to get a taste of this on Wednesday with highs rebounding to the 60s in many spots after some early-day scattered clouds and possibly some patchy fog. Sunshine will be more abundant later in the day.
Thursday looks to be a bit warmer with many spots from Seattle south reaching the 70s again. A very minor disturbance moving across the region will bring more clouds to the picture for Friday with slightly cooler temperatures, but still with the mid to upper 60s in Seattle to wind up the work week, highs will still be about four to five degrees above average.
Saturday is the unofficial “start of boating season” for Western Washington with the Windermere Cup regatta along Seattle’s Montlake Cut. Morning clouds turning to afternoon sunshine will bring high temperatures back close to 70.
By this weekend, when the sun is out, the UV Index will be nosing into the high category with an index level of 6. Despite our northerly latitude and reputation for dark and gray days, this level of ultraviolet radiation can burn unprotected skin in less than half an hour. Make sure to use sunscreen, wear a hat and sunglasses for protection!
The sun’s rays are strongest in the hours before and after “solar noon” when the sun it at the highest point in the sky. For us in early May, that’s just after 1 pm.
By Sunday, the cooling effects of the Pacific Ocean (and the air flowing atop it) will be shut off due to easterly and northerly wind flow. This is one factor that will allow high temperatures to climb into the upper 70s for both Sunday and Monday. There will be some 80s in the warmest spots.
The record high for Sunday in Seattle is 77° set back in 1992, but it’s worth noting that this is the coldest daily record high of the entire month of May! With a forecast high around 78°, we’ll likely “prune” that one from the record books.
If we get to 80°, that would feel like summer for sure, but it’s not unheard of:
- The average first 80° or higher day in Seattle is May 20th.
- The earliest we’ve ever hit 80° or higher is April 1st, 1987.
- The longest we’ve ever had to wait for an 80° or higher temperature was July 21st, back in 1980.
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