Snohomish River Run weather.

Typically 11°C on race morning; rain in 4 of the last 10 years. Race morning (07:00 to 11:00 local time) in Snohomish on race day in each of the last 10 years; the 2027 race is on 17 Oct 2027.

Typical
11°C (52°F)
race-morning average
Coolest
0°C (32°F)
lowest reading, 07:00–11:00
Warmest
24°C (75°F)
highest reading, 07:00–11:00
Wet years
4 of 10
rain, drizzle or worse
Humidity
90%
typical
Wind
7 km/h
typical, at 10 m

Race morning, 07:00–11:00

Year by year

Race dayAverageLow–highHumidityWindRainConditions
19 Oct 202510°C (51°F)9°C (49°F)–12°C (53°F)91%24 km/h2.1 mmOvercast
20 Oct 202415°C (58°F)14°C (56°F)–17°C (62°F)92%11 km/h0.0 mmOvercast
15 Oct 202312°C (54°F)10°C (50°F)–16°C (60°F)93%5 km/h0.0 mmOvercast
16 Oct 202216°C (62°F)11°C (52°F)–24°C (75°F)50%5 km/h0.0 mmClear
17 Oct 202111°C (52°F)10°C (50°F)–13°C (55°F)85%4 km/h0.2 mmOvercast
18 Oct 202011°C (52°F)10°C (49°F)–13°C (55°F)98%11 km/h4.5 mmHeavy drizzle
20 Oct 20197°C (45°F)7°C (44°F)–9°C (48°F)98%10 km/h0.5 mmLight drizzle
14 Oct 20185°C (40°F)0°C (31°F)–12°C (53°F)79%3 km/h0.0 mmClear
15 Oct 20177°C (44°F)3°C (38°F)–12°C (53°F)80%3 km/h0.0 mmClear
16 Oct 201611°C (51°F)10°C (51°F)–12°C (53°F)90%14 km/h2.5 mmDrizzle

Each row is the race's date that year where we know it, else the same weekday nearest its usual date. Temperatures and humidity are averaged over 07:00 to 11:00 local time, rain is the total over those hours, and conditions are the commonest over the morning. The marathon starts at 07:30.

Kit and pacing

What it means

  • Good racing weather

    Around 11°C is close to ideal for a fast time. Shorts and a vest are enough once you're moving; bring a throwaway layer for the wait in the start pen.

  • Have a warm-day plan

    In the warmest of these years it reached 24°C by late morning. Decide in advance how much you'd slow down if the forecast is warm, rather than on the course.

  • It can be cold

    The coolest morning here dropped to 0°C. Pack gloves and a throwaway layer even if the forecast looks kind.

  • Be ready for rain

    It rained on 4 of the last 10 race mornings. A bin bag or cheap poncho keeps you dry in the start pen; anti-chafe balm and socks that don't hold water help over the distance, and a cap keeps rain out of your eyes.

  • The weather varies a lot

    Race mornings here have ranged by 12°C from year to year. Pack for both, and settle your kit and pacing from the forecast in the last few days.

General guidance from past years' numbers. Check the forecast in race week.

The course 2027 dates and entry

Weather data by Open-Meteo.com, from its historical weather archive (CC BY 4.0).

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