Seattle Half Marathon

Runners will start in chilly 36°F conditions — dress in layers for the corral and plan to shed early. Moderate humidity at 78% is worth noting for effort level, especially in later miles.

Race day forecast available in 42 days

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Distance: 13.1mi

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Race Info

The Seattle Half Marathon starts at Seattle Center and finishes at Bell Harbor Pier 66 on the downtown Seattle waterfront. The course covers about 13.1 miles through Seattle's parks, waterways and viewpoints. It runs on the Sunday of race weekend.

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Race weekend

Sunday, November 29

7:00 AMMarathon (26.2 mi)

8:30 AMHalf Marathon (13.1 mi)

FAQ

When is the 2026 Seattle Half Marathon?

The 2026 Seattle Half Marathon will be held on Sunday November 29, 2026.

What will the weather be like for the 2026 Seattle Half Marathon?

The forecast calls for a high of 45°F and a low of 35°F with a 25% chance of rain. Check our detailed hourly forecast above for the best half marathon race plan.

Historical Weather

Based on 25 years of data

Avg Temp

42°F

L:41° H:43°

RunScore

Conditions

Rain Freq

20%

5 of 25 yrs

Wind8mph

Dew38°F

Temperature History

Range of temperatures during race hours for each year.

Detailed History

Year	Low / High	Rain	Dew Point
2025 Seattle Half Marathon Clearing in the afternoon. 2025	30°/34°	-	31°
2024 Seattle Half Marathon Clearing in the afternoon. 2024	34°/39°	-	35°
2023 Seattle Half Marathon Clearing in the afternoon. 2023	32°/35°	-	32°
2022 Seattle Half Marathon Cloudy skies throughout the day. 2022	37°/40°	-	36°
2021 Seattle Half Marathon Cloudy skies throughout the day with afternoon rain. 2021	59°/60°	-	48°
2019 Seattle Half Marathon Cloudy skies throughout the day. 2019	42°/44°	-	26°
2018 Seattle Half Marathon Partly cloudy throughout the day. 2018	36°/41°	-	35°
2017 Seattle Half Marathon Partly cloudy throughout the day with a chance of rain throughout the day. 2017	52°/55°	Light	52°
2016 Seattle Half Marathon Cloudy skies throughout the day with a chance of rain throughout the day. 2016	43°/45°	-	43°
2015 Seattle Half Marathon Cloudy skies throughout the day. 2015	33°/34°	-	31°
2014 Seattle Half Marathon Clear conditions throughout the day. 2014	28°/30°	-	21°
2013 Seattle Half Marathon Partly cloudy throughout the day with early morning rain. 2013	55°/55°	-	43°
2012 Seattle Half Marathon Partly cloudy throughout the day. 2012	39°/41°	-	38°
2011 Seattle Half Marathon Cloudy skies throughout the day with a chance of rain throughout the day. 2011	51°/54°	Light	46°
2010 Seattle Half Marathon Partly cloudy throughout the day. 2010	38°/40°	-	37°
2009 Seattle Half Marathon Cloudy skies throughout the day. 2009	51°/51°	-	45°
2008 Seattle Half Marathon Cloudy skies throughout the day with rain clearing later. 2008	53°/54°	-	52°
2007 Seattle Half Marathon Clearing in the afternoon. 2007	33°/39°	-	35°
2006 Seattle Half Marathon Cloudy skies throughout the day with a chance of rain or snow throughout the day. 2006	36°/38°	Light	33°
2005 Seattle Half Marathon Partly cloudy throughout the day with rain clearing later. 2005	37°/39°	-	35°
2004 Seattle Half Marathon Partly cloudy throughout the day. 2004	40°/41°	-	38°
2003 Seattle Half Marathon Partly cloudy throughout the day. 2003	41°/42°	-	38°
2002 Seattle Half Marathon Partly cloudy throughout the day. 2002	43°/45°	-	41°
2001 Seattle Half Marathon Cloudy skies throughout the day with rain in the morning and afternoon. 2001	44°/44°	Light	40°
2000 Seattle Half Marathon Cloudy skies throughout the day with a chance of rain throughout the day. 2000	48°/50°	Light	43°