The 2026 Green River Run With the Horses Half Marathon has concluded.

Green River Run With the Horses Half Marathon

Race complete
Green River, WY, USA · August 15, 2026·
partly-cloudy-day55°·61° high·Breezy·Dry
8
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Green River Run With the Horses Half Marathon race day weather

clear-day
55°at start
77° high
Breezy
Dry
Your goal
0:00:00

Comfortable temps, big temp swing, moderate wind

Mild 55°F temps at gun time mean comfortable early miles without overheating risk. Temps will climb significantly to 77°F by later miles, so expect fading conditions as the race progresses. Moderate winds around 13mph may affect pacing on open sections of the course.

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About the Green River Run With the Horses Half Marathon

The Run With the Horses Half Marathon starts in front of the pavilion on Expedition Island in Green River, Wyoming, at 6,100 feet. After two miles of city streets and the paved Greenbelt Trail along the Green River, it turns onto the county-graded dirt Wild Horse Loop Tour Road and climbs 1st Springs Canyon to the top of White Mountain, where the rolling course runs between 7,300 and 7,500 feet. The turnaround comes at the halfway point on the high plains desert, with little shade and open views of wild horses and other wildlife, and runners return the same way to Expedition Island. It is run on the Saturday of River Festival weekend.

Race weekend

Saturday, August 15
7:00 AMMarathon (26.2 mi)
7:00 AMHalf Marathon (13.1 mi)
7:00 AM10K (6.2 mi)
7:00 AM5K (3.1 mi)
Area Map
Course Map

Green River Run With the Horses Half Marathon FAQ

When is the 2026 Green River Run With the Horses Half Marathon?

The 2026 Green River Run With the Horses Half Marathon will be held on Saturday August 15, 2026.

What will the weather be like for the 2026 Green River Run With the Horses Half Marathon?

The forecast calls for a high of 79°F and a low of 55°F with a 0% chance of rain. Check our detailed hourly forecast above for the best half marathon race plan.

What is the weather usually like for the Green River Run With the Horses Half Marathon?

Over the 22 years racecast.io has race-day weather for (2004 to 2026), it averaged 54°F at the start and 61°F by a typical finish. It has not rained during race hours in any of those years.

What was the hottest Green River Run With the Horses Half Marathon?

Of the 22 years on record, 2013 was the warmest, reaching 70°F during race hours. The coldest start was 2016, at 38°F.

What was the windiest Green River Run With the Horses Half Marathon?

Of the 22 years on record, 2006 was the windiest, with wind averaging 10 mph during race hours. The calmest was 2013, at 0 mph.

Green River Run With the Horses Half Marathon weather history

Based on 22 years of data
Avg Temp
57°F
L:54° H:61°
RunScore
9
Conditions
Rain Freq
0%
0 of 22 yrs
Wind4mph
Dew37°F

Temperature History

Range of temperatures during race hours for each year.

Detailed History

YearConditionsLow / HighRainScoreResults
2026
partly-cloudy-day
55°/61°-
8
2025
clear-day
53°/62°-
8
2024
clear-day
55°/68°-
8
2023
clear-day
59°/67°-
7
2022
clear-day
54°/57°-
8
2021
clear-day
48°/55°-
10
2020
clear-day
52°/63°-
9
2019
clear-day
51°/62°-
9
2018
clear-day
52°/58°-
9
2017
clear-day
58°/65°-
9
2016
clear-day
38°/48°-
10
2015
partly-cloudy-day
63°/67°-
7
2014
clear-day
58°/67°-
8
2013
clear-day
64°/70°-
8
2012
clear-day
54°/62°-
9
2010
clear-day
59°/69°-
7
2009
clear-day
59°/65°-
9
2008
partly-cloudy-day
54°/58°-
10
2007
clear-day
51°/58°-
10
2006
clear-day
48°/52°-
10
2005
clear-day
53°/60°-
10
2004
clear-day
41°/49°-
10