The 2026 Green River Marathon has concluded.

Green River Marathon

Race complete

Kent, WA, USA · June 6, 2026

52°·60° high·Breezy·Dry

Race Day Weather

52°at start

61° high

Breezy

Dry

Cool temps, manageable humidity

Runners will face a steady temperature range from 51°F to 61°F with average humidity at 64%. Wind will be from the SW at 13 mph, possibly gusting to 22 mph. Given the conditions, pacing should be conservative early on to adapt to the slight increases in temperature.

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Race Info

The Green River Marathon, a volunteer-run event in Kent, WA, offers a flat and fast course with picturesque views. Runners enjoy a scenic journey along the Green River Trail, culminating in a finish with views of Seattle, Puget Sound, and the Olympic Mountains. This community-focused race emphasizes a low-key, friendly atmosphere, and historically operates with no entry fee, instead relying on donations to support Northwest Harvest.

Website

Course Map

FAQ

When is the 2026 Green River Marathon?

The 2026 Green River Marathon will be held on Saturday June 6, 2026.

Is the Green River Marathon a Boston Marathon Qualifier?

Yes, the Green River Marathon is an official Boston Marathon qualifier.

What is the time limit for the Green River Marathon?

The time limit for the Green River Marathon is 6 hours.

What will the weather be like for the 2026 Green River Marathon?

The forecast calls for a high of 61°F and a low of 50°F with a 100% chance of rain.

Historical Weather

Based on 18 years of data

Avg Temp

68°F

L:57° H:68°

RunScore

Conditions

Rain Freq

11%

2 of 18 yrs

Wind10mph

Dew48°F

Temperature History

Range of temperatures during race hours for each year.

Detailed History

Year	Low / High	Rain	Dew Point
2025 Green River Marathon Partly cloudy throughout the day. 2025	62°/77°	-	53°
2024 Green River Marathon Partly cloudy throughout the day. 2024	55°/62°	-	47°
2023 Green River Marathon Clear conditions throughout the day. 2023	55°/70°	-	44°
2022 Green River Marathon Partly cloudy throughout the day with late afternoon rain. 2022	58°/68°	-	51°
2021 Green River Marathon Partly cloudy throughout the day. 2021	55°/64°	-	46°
2020 Green River Marathon Partly cloudy throughout the day with afternoon rain. 2020	54°/61°	-	46°
2017 Green River Marathon Partly cloudy throughout the day. 2017	57°/63°	-	46°
2016 Green River Marathon Clear conditions throughout the day. 2016	67°/80°	-	55°
2015 Green River Marathon Partly cloudy throughout the day. 2015	64°/80°	-	52°
2014 Green River Marathon Partly cloudy throughout the day. 2014	57°/70°	-	51°
2013 Green River Marathon Partly cloudy throughout the day. 2013	56°/69°	-	46°
2012 Green River Marathon Partly cloudy throughout the day with rain clearing later. 2012	54°/65°	Light	49°
2011 Green River Marathon Clear conditions throughout the day. 2011	56°/74°	-	50°
2010 Green River Marathon Clearing in the afternoon with rain clearing later. 2010	54°/66°	Light	46°
2009 Green River Marathon Cloudy skies throughout the day with morning rain. 2009	57°/61°	-	53°
2008 Green River Marathon Cloudy skies throughout the day. 2008	49°/56°	-	44°
2007 Green River Marathon Partly cloudy throughout the day. 2007	62°/77°	-	48°
2006 Green River Marathon Partly cloudy throughout the day. 2006	57°/68°	-	48°

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