Seattle weather forecast: Sunny and warm weekend, then chance of rain

Another sunny weekend is on tap across the Seattle area, followed by a chance for the first droplets of rain to fall since nearly one month ago. 

A ridge of high pressure building over the western side of the country will cause the mercury to dance up the thermometer through Sunday, according to the National Weather Service.

Few, if any, clouds on Friday were expected to cause temperatures to rise quickly, as highs climb into the low to mid-80s across the Seattle area, the weather service said. 

The air mass remains on the dry side, though, so temperatures were expected to drop into the 50s overnight heading into Saturday, providing some relief from the heat. 

The ridge of high pressure is expected to peak Saturday, causing high temperatures to jump a few degrees more, reaching the mid- to upper 80s — nearly 15 degrees above normal for this time of year — across the region.

High clouds will also be present Saturday, but they won’t do anything to dampen the heat, said Trent Davis, a meteorologist with the weather service in Seattle.

There is a 20% to 40% chance that highs will jump above 90 degrees Saturday in the southwest interior, especially around the South Puget Sound areas of Thurston and Mason counties, the weather service said.

Overnight lows will again cool into the 50s heading into Sunday as the ridge of high pressure shifts eastward.

Cloud cover nudging in from the coast on Sunday will keep temperatures slightly lower — but still in the 80s — across the Seattle area to wrap up the weekend.

A system drifting in from the coast over British Columbia is expected to start scattering showers into the region Sunday evening through Monday, especially north of Seattle.

Seattle’s greatest chance of rain in the near future will arrive with this system on Monday, “but the amounts are going to be really light, just a few hundredths to maybe — if we’re lucky — a tenth of an inch of rain. So, not a whole lot to really help with the drought conditions we’re seeing, unfortunately,” Davis said early Friday.

Snohomish, Skagit and Whatcom counties, as well as the Northern Olympic Peninsula, have a 30% to 50% chance of getting rainfall over a tenth of an inch, the weather service said.