Green River Marathon

Kent, WA, USA · June 6, 2026
partly-cloudy-day55°·64° high·Light·Dry
9
Register
Weather
Course
Race Info
FAQ
History

Race Day Weather

partly-cloudy-day
55°at start
65° high
Light
Dry

Cool start, manageable conditions

Runners will face a temperature rising from 50°F to 65°F, with an average humidity of 63% and a dew point of 46°F. Winds from the WSW at 6 mph will gust up to 20 mph, creating a slight headwind. Runners should maintain their pace but stay hydrated, particularly as temperatures increase.

Race day forecast available in 4 days
partly-cloudy-day9
partly-cloudy-day9
partly-cloudy-day9
partly-cloudy-day9
partly-cloudy-day9
partly-cloudy-day9
partly-cloudy-day9
partly-cloudy-day9
partly-cloudy-day9
partly-cloudy-day9
partly-cloudy-day9

Get forecast alerts for Green River Marathon

We'll text or email you when the forecast shifts — so you can adjust gear, pacing, and strategy. Max one per day.

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
Area Map

Course Map

Course Map Unavailable

We don't have course map data for Green River Marathon yet. If you have a GPX file (or other format) for this race, we'd love to add it!

FAQ

Ask a Question about the Green River Marathon

Racecast Concierge (free during beta)

Ask a question about the Green River Marathon and we'll do the hard part and find the answer for you within 48 hours.

By using Racecast Concierge, you agree to receive email alerts pertaining to the Green River Marathon and general racecast.io updates.

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 66°F and a low of 48°F with a 18% chance of rain.

Historical Weather

Based on 18 years of data
Avg Temp
68°F
L:57° H:68°
RunScore
8
Conditions
Rain Freq
11%
2 of 18 yrs
Wind10mph
Dew48°F

Temperature History

Range of temperatures during race hours for each year.

Detailed History

YearConditionsLow / HighRainScore

2025 Green River Marathon

Partly cloudy throughout the day.

2025
partly-cloudy-day
62°/77°-
8

2024 Green River Marathon

Partly cloudy throughout the day.

2024
cloudy
55°/62°-
9

2023 Green River Marathon

Clear conditions throughout the day.

2023
clear-day
55°/70°-
9

2022 Green River Marathon

Partly cloudy throughout the day with late afternoon rain.

2022
partly-cloudy-day
58°/68°-
9

2021 Green River Marathon

Partly cloudy throughout the day.

2021
cloudy
55°/64°-
7

2020 Green River Marathon

Partly cloudy throughout the day with afternoon rain.

2020
partly-cloudy-day
54°/61°-
8

2017 Green River Marathon

Partly cloudy throughout the day.

2017
cloudy
57°/63°-
9

2016 Green River Marathon

Clear conditions throughout the day.

2016
clear-day
67°/80°-
7

2015 Green River Marathon

Partly cloudy throughout the day.

2015
partly-cloudy-day
64°/80°-
8

2014 Green River Marathon

Partly cloudy throughout the day.

2014
partly-cloudy-day
57°/70°-
9

2013 Green River Marathon

Partly cloudy throughout the day.

2013
cloudy
56°/69°-
9

2012 Green River Marathon

Partly cloudy throughout the day with rain clearing later.

2012
cloudy
54°/65°Light
8

2011 Green River Marathon

Clear conditions throughout the day.

2011
clear-day
56°/74°-
8

2010 Green River Marathon

Clearing in the afternoon with rain clearing later.

2010
partly-cloudy-day
54°/66°Light
8

2009 Green River Marathon

Cloudy skies throughout the day with morning rain.

2009
cloudy
57°/61°-
9

2008 Green River Marathon

Cloudy skies throughout the day.

2008
cloudy
49°/56°-
9

2007 Green River Marathon

Partly cloudy throughout the day.

2007
partly-cloudy-day
62°/77°-
8

2006 Green River Marathon

Partly cloudy throughout the day.

2006
partly-cloudy-day
57°/68°-
9

More WA Races

Last Chance Marathon
2026-12-31 · Bellingham, WA, USA
Light at the End of the Tunnel Marathon
2026-06-07 · North Bend, WA, USA
Super Marathon
2026-06-13 · North Bend, WA, USA
Jack and Jills Downhill Marathon (Saturday)
2026-07-25 · North Bend, WA, USA
Jack and Jills Downhill Marathon (Sunday)
2026-07-26 · North Bend, WA, USA
Tunnel Vision Marathon
2026-08-09 · North Bend, WA, USA
Free guidesMarathon Fueling Guide·Carb Loading Guide·Race Morning Guide·Race Day Gear Guide·Pacing Strategy Guide·Mental Strategy Guide

Race Day Alerts

Get notified when the Green River Marathon forecast shifts — so you can adjust your gear, pacing, and strategy.

Forecast shift alerts (temp, wind, rain)
Updates as weather changes leading up to race day
Max one message per day
Text Alerts

USA, UK, and Canada only. Standard rates apply.

or
Email Alerts

By subscribing you agree to receive race forecasts and racecast.io updates.

Submit a correction

Spot something wrong or missing for the Green River Marathon? Let us know and we'll update it.

You Need an Account For That

Setting up a racecast.io account will allow you to start building a reputation in the community. Over time you'll be able to rate races, join the discussion, and post in the community.

Right now we are invite only, you can get on the waitlist by entering your email below:

OR

Submit a race

Missing a race? Send it in and we'll add it to Racecast.