Labor Day weekend forecast: Drier weather and some sunshine expected after midweek rain

On Tuesday of this week, Sept. 1 marks the beginning of meteorological fall. Yes, the astronomical summer season continues until the fall equinox, which this year falls on Sept. 22 near 5 p.m. Yet, the meteorological fall months of September, October, and November better represent what the time of year feels like.

Weather-wise, it will feel like fall starting Tuesday night and the rest of the week. A Pacific weather system tracking southeast from the Gulf of Alaska is set to swing onshore, bringing more widespread rain Wednesday. Scattered showers are expected in the wake of this weather system Thursday, tapering off Friday.

Besides the fall-like rainfall, high temperatures will also feel like autumn weather. Readings are expected to cool mainly into the 60s to perhaps as warm as 70.

For Monday and Tuesday of this week, milder summer weather is in store with a mix of clouds and sunshine. High temperatures are expected to be mainly in the 70s, before the cool down begins on Wednesday.

Labor Day weekend outlook

Higher pressure aloft is forecast to build over Washington as the Labor Day holiday weekend unfolds. Drier weather with some sunshine and high temperatures close to average for this time of the year, right around 70 degrees.

Eastern Washington is expected to feel this significant change in the weather pattern later this week. Some rainfall is anticipated with high temperatures cooling into the 60s and 70s. The drying trend for the holiday weekend is forecast to be slower than in western Washington, with lingering showers tapering off Saturday into Sunday.

Rainfall east of the Cascades is not expected to be enough to douse the ongoing wildfires. Yet, the rain and cooler temperatures will help dampen fire activity and improve air quality from wildfire smoke.

The mountains this holiday weekend are forecast to dry out over the holiday weekend, with freezing levels in the 7,000 to 9,000 foot range.

For those with holiday camping plans, statewide burn bans remain in place. Use only grated campfire pits, or use gas-fueled grills. Ensure any campfires are cold before leaving the campground.

Meteorological fall vs. winter

Meteorological fall is September, October, and November. The months of December, January, and February mark meteorological winter — the coldest months, while June, July, and August are the hottest months of the year and are meteorological summer.

Astronomical fall, commonly called the first day of fall, starts with the fall equinox on Sept. 22 and runs through until the winter solstice, or the shortest day of the year, in late December. So the difference between the astronomical and meteorological seasons simply comes down to the start and end dates.

Regardless, fall is just around the corner as the days get shorter, nights grow longer, and cooler, wetter weather returns. In the meantime, enjoy what summer weather remains!

Ted Buehner is the KIRO Newsradio meteorologist. Follow him on X and Bluesky. Read more of his stories here.