Seattle woke up to clear, cool air early Monday, with temperatures at about 46°F at Boeing Field as of 5:40 a.m. on May 18, 2026. The classic May fake-out is in play: patchy low clouds and fog in a few spots to start, then sunshine for most neighborhoods by midmorning. Highs should head for the mid-60s this afternoon, and overnight lows will dip back into the upper 40s. A light jacket makes sense for the morning commute, but you can plan on a dry, comfortable afternoon.
Afternoon And Midweek Outlook
Expect mostly sunny skies with a high near 66°F today, with similar highs stacked up through Wednesday. A ridge sitting offshore keeps the pattern dry while still allowing a gentle onshore breeze and light north winds along the water. By Thursday, temperatures creep into the low 70s, setting up a pleasantly mild finish to the workweek.
Boaters Should Watch The Strait
A Small Craft Advisory is in effect for the central Strait of Juan de Fuca from 2 p.m. Monday, May 18, 2026, through 5 a.m. Tuesday, May 19, 2026. Seas are expected to run 6 to 8 feet with gusty onshore winds, which will make for choppy conditions for smaller vessels this afternoon and overnight. Gusts could reach about 30 mph along Whidbey Island at times, and some delays or rough rides on local ferry routes are possible. Mariners and recreational boaters should monitor conditions closely and plan around the advisory, according to NWS Seattle.
Commutes, Flights And Fog
A few pockets of morning stratus or fog could briefly knock down visibility in parts of the South Sound and the Kitsap Peninsula, but most roads should improve by midmorning. Local airports are expected to stay in VFR territory, although a handful of terminals might see brief MVFR ceilings early on. By the afternoon rush, KSEA is expected to remain mostly clear. If you have outdoor plans before breakfast, give yourself a little extra time for the cool start and keep a light layer handy.
Looking Ahead
High pressure offshore keeps things mostly dry through midweek, with only a slight chance of light sprinkles in the mountains. Ensemble guidance hints at a turn toward a wetter setup by late next weekend, with rising odds of more widespread rain Sunday evening, May 24, 2026. That is worth keeping an eye on if you are banking on outdoor plans. For context and earlier coverage of the marine pattern, see our look at the cool skies and choppy seas.
