Seattle Marathon
Race Day Weather
Cool start, mild finish
Runners will face a temperature rise from 35°F at the start to a peak of 42°F. Humidity will be high at 78%, so adjustments to pacing are advisable, especially in the middle segments. Wind will be light but will shift from headwind to tailwind, with tougher conditions expected during miles 4-5 and 21. Proper hydration should be prioritized throughout the race.
Pace Calculator
Get forecast alerts for Seattle Marathon
We'll text or email you when the forecast shifts — so you can adjust gear, pacing, and strategy. Max one per day.
Get your personalized Seattle Marathon race plan
True Effort pacing, weather-adjusted mile splits, fueling timeline with aid stations, packing checklist, carb tracker, spectator guide — all personalized to your goal and race-day conditions.
Race Info
The Seattle Marathon starts at Seattle Center and finishes at Bell Harbor Pier 66 on the downtown waterfront. A new course introduced for the 2025 race takes runners north along Lake Union's Eastlake shore, across the Montlake Bridge, and through Interlaken Park into the Washington Park Arboretum and the University of Washington campus, then west past Gas Works Park and through Fremont before finishing on the waterfront. First run in 1970 by a group of University of Washington friends, it's the oldest marathon in the Pacific Northwest and still pairs a half marathon with the full on race morning.
