Green River Marathon

Kent, WA, USA · June 5, 2027

55°·60° high·Light·Dry

Weather

Race Day Weather

55°at start

65° high

Light

Dry

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Cool conditions, slight humidity

Runners will face a temperature trend from 55°F at the start to 60°F by finish, with humidity around 66% and a dew point of 47°F. Winds will be light from the W at 7 mph, not significantly affecting performance. Runners should consider starting conservatively to manage the humidity and ensure hydration throughout the race.

Race day forecast available in 207 days

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Distance: 26.2mi

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Race Info

The Green River Marathon is a free, donation-supported marathon, half marathon, and 50K held each June in Kent, Washington. The course follows the Green River Trail as an out-and-back route starting and finishing at Three Friends Fishing Hole. It is a USATF-certified Boston qualifier and has run annually since 1997, reaching its 31st running in 2027. The race is organized entirely by volunteers, with no entry fee, official awards, or paid staff.

Website

Race weekend

Saturday, June 5

8:00 AMMarathon (26.2 mi)

Half Marathon (13.1 mi)

50K (31.1 mi)

Course Map

FAQ

When is the 2027 Green River Marathon?

The 2027 Green River Marathon will be held on Saturday June 5, 2027.

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 2027 Green River Marathon?

The forecast calls for a high of 66°F and a low of 48°F with a 14% chance of rain. Check our detailed hourly forecast above for the best marathon race plan.

Historical Weather

Based on 19 years of data

Avg Temp

61°F

L:57° H:64°

RunScore

Conditions

Rain Freq

11%

2 of 19 yrs

Wind7mph

Dew49°F

Temperature History

Range of temperatures during race hours for each year.

Detailed History

Year	Low / High	Rain	Dew Point
2026 Green River Marathon Partly cloudy throughout the day with afternoon rain. 2026	52°/59°	-	44°
2025 Green River Marathon Partly cloudy throughout the day. 2025	62°/70°	-	53°
2024 Green River Marathon Partly cloudy throughout the day. 2024	55°/60°	-	47°
2023 Green River Marathon Clear conditions throughout the day. 2023	55°/66°	-	45°
2022 Green River Marathon Partly cloudy throughout the day with late afternoon rain. 2022	58°/66°	-	51°
2021 Green River Marathon Partly cloudy throughout the day. 2021	55°/62°	-	47°
2020 Green River Marathon Partly cloudy throughout the day with afternoon rain. 2020	54°/60°	-	46°
2017 Green River Marathon Partly cloudy throughout the day. 2017	57°/61°	-	47°
2016 Green River Marathon Clear conditions throughout the day. 2016	67°/76°	-	55°
2015 Green River Marathon Partly cloudy throughout the day. 2015	64°/75°	-	52°
2014 Green River Marathon Partly cloudy throughout the day. 2014	57°/67°	-	51°
2013 Green River Marathon Partly cloudy throughout the day. 2013	56°/66°	-	47°
2012 Green River Marathon Partly cloudy throughout the day with rain clearing later. 2012	54°/60°	Light	50°
2011 Green River Marathon Clear conditions throughout the day. 2011	56°/69°	-	50°
2010 Green River Marathon Clearing in the afternoon with rain clearing later. 2010	54°/62°	Light	45°
2009 Green River Marathon Cloudy skies throughout the day with morning rain. 2009	57°/58°	-	53°
2008 Green River Marathon Cloudy skies throughout the day. 2008	49°/53°	-	44°
2007 Green River Marathon Partly cloudy throughout the day. 2007	62°/72°	-	48°
2006 Green River Marathon Partly cloudy throughout the day. 2006	57°/64°	-	48°

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