Seattle's long Memorial Day weekend will begin with clear, warm weather: on Thursday and Friday temperatures will climb to 22–23°C (low 70s°F) with abundant sunshine and a light haze of clouds. But meteorologist Jeff Mihalewski warns that swimming at local beaches can be dangerous — the water remains icy and some areas are polluted. Those looking to cool off should choose other recreational options.
By Sunday it will be cooler — the air will drop to around 18°C (mid-60s°F), and the weekend will end Monday with rain and temperatures near 12°C (50°F). Moisture will arrive from the coast, bringing precipitation inland. Travelers should account for traffic jams — red brake lights can spoil the mood even on sunny days.
Based on: Seattle weather for Memorial Day weekend: nice and sunshine-y at first