Seattle woke up to clear skies and a cool 55°F at Boeing Field on Sunday, but the reprieve will be short-lived. The region is sliding into a multi-day stretch of heat with sunny afternoons, warmer nights, and not much overnight relief. A Heat Advisory is in effect from 11 AM Monday, June 22, through 11 PM Wednesday, June 24, so get ready for some uncomfortably warm days.
What To Expect
Sunday stays pleasant around 78°F, but the thermostat inches up from there. Monday is expected to reach about 84°F, with a peak near 88°F on Tuesday, and some interior valleys are forecast to climb into the low 90s. Nighttime lows in the upper 50s to low 60s mean many homes will not cool off much after dark. The Heat Advisory, running 11 AM Monday through 11 PM Wednesday, comes from the National Weather Service, which warns the heat "will significantly increase the risk of heat-related illness" for anyone without effective cooling.
Where It Will Feel Hottest
Inland neighborhoods and the Eastside will bear the brunt of the heat, while communities right along Puget Sound should stay a few degrees cooler. Humidity is expected to remain generally low, but that dry air, combined with a strengthening ridge, brings elevated fire-weather concerns in some foothill and valley locations. Outdoor workers should shift heavy tasks to early morning or evening as much as possible and take frequent water breaks.
Cooling And Safety
Public health advice here is simple and not exactly optional: drink plenty of water, stay out of direct sun during the hottest midday hours, and never leave children or pets in a parked car, even for a short time. For help tracking down a cooling center or other services, call 2-1-1 or visit WA 211. It is also a good time to check in on neighbors who are older, have medical issues, or do not have air conditioning.
Outlook
Relief is on the way, just not immediately. Onshore flow is forecast to return later in the week, bringing a noticeable cooldown and a chance of light rain by Thursday and Friday. Highs should slide back into the 60s and 70s once the advisory expires. Mariners should keep an eye out for building seas by midweek, and anyone planning outdoor activities later in the week should check updated forecasts before heading out.
