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Race-day weather · Wyndo for runners

Seattle Marathon weather

November 29, 2026 · Seattle, WA · scheduled start 7:00 AM (America/Los_Angeles). What the start usually feels like, year by year — and a live start-time read once the race is inside the 7-day forecast window.

Countdown

139 days to race day

The live race-day forecast unlocks 133 days from now, when November 29, 2026 enters the 7-day forecast window — a start-time read for the scheduled 7:00 AM start. Until then, no made-up long-range forecast — the history below is what race morning usually looks like.

Typical start temp

40°F

median of 20 years

A warm year

49°F

75th percentile start temp

Rain at the start

30%

6 of 20 measured years

Race-morning weather history

Cool rain is the norm for late-November Seattle — plan for 40s F and wet. Wyndo tracks what this calendar slot has actually served up at the start hour — temperature, dew point, wind, and rain — including the years when weather canceled or disrupted the race, and reads the live forecast for the start once race week arrives.

Median start temp

40°F

p75 (a warm year): 49°F

Median dew point

38°F

at the start hour

Rain at the start

30%

6 of 20 measured years

Warmest start

57°F

in 2021

Start-hour weather by year for the Seattle Marathon's calendar slot
YearStart tempDew pointWindPrecip (start hr)Day's high
202536°F33°F3 mphdry46°F
202437°F35°F3 mphdry48°F
202333°F31°F5 mphdry47°F
202241°F37°F3 mph0.2 mm47°F
202157°F52°F13 mphdry58°F
202039°F38°F4 mphdry48°F
201938°F30°F5 mph0.2 mm43°F
201840°F37°F2 mphdry49°F
201753°F47°F7 mph0.5 mm53°F
201644°F43°F5 mphdry47°F
201532°F30°F3 mphdry38°F
201424°F21°F5 mphdry36°F
201352°F50°F16 mph1.3 mm52°F
201242°F38°F2 mphdry46°F
201153°F39°F14 mphdry54°F
201040°F40°F3 mph0.2 mm41°F
200949°F47°F9 mphdry52°F
200853°F53°F2 mphdry55°F
200739°F38°F3 mphdry44°F
200638°F31°F10 mph1.0 mm41°F

Slot climatology, honestly framed: each row is the weather at this race's usual calendar slot and start hour (ERA5 reanalysis at the start line) — including years when the edition was canceled or moved, because what the slot serves up is exactly the question. A computed slot date is not a claim the race ran that day.

Your heat-adjusted goal for the marathon

The same cited model as the full calculator, pointed at this race: the median start-hour conditions this calendar slot has served up — climatology, not a forecast.

Training for this race?

Wyndo can email you when conditions turn good for a run near Seattle, WA — and stay quiet when they don't. (A race-week forecast alert keyed to race day is coming next.)

Get an alert when it's a good time for running

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Race facts

Start line
Seattle Center, 5th Ave N & Harrison St
Scheduled start
7:00 AM (America/Los_Angeles) — Half starts 7:00, full marathon 7:30, per official 2026 page; start at Seattle Center (5th & Harrison), finish at Bell Harbor Pier 66 — a changed start/finish from prior Memorial Stadium editions.
Field size
2025 marathon finishers ~1,500; half ~4,200
Registration
open

Wyndo is not affiliated with or endorsed by the Seattle Marathon (officially the "UW Medicine Seattle Marathon and Half Marathon") or its organizers. Race names are used descriptively to identify the event; schedules and start times belong to the race — always confirm details on the official site. Weather guidance here is informational, never medical advice, and event alert flags on race day belong to the race's own medical team.