Runners will face a temperature rise from 59°F at the start to a warm 79°F by the finish. Winds will be light at 7 mph from the SSW, with gusts up to 21 mph. With humidity at 62%, pacing adjustments are advised as the race progresses, particularly in the warmer afternoon.

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Pace Calculator

Distance: 26.2mi

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Race Info

This amazing run course will take you alongside the Boulder Reservoir, remaining mostly on dirt roads and trails. The course is flat with only 200 feet of gain, and will provide views of the Boulder Reservoir and Rocky Mountains. Source

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Race weekend

Saturday, August 15

7:15 AMMarathon (26.2 mi)

7:20 AM3/4 Marathon (19.7 mi)

7:25 AMHalf Marathon (13.1 mi)

7:30 AM10K (6.2 mi)

Course Map

FAQ

When is the 2026 Boulder Rez Marathon?

The 2026 Boulder Rez Marathon will be held on Saturday August 15, 2026.

Is the Boulder Rez Marathon a Boston Marathon Qualifier?

Yes, the Boulder Rez Marathon is an official Boston Marathon qualifier.

What is the time limit for the Boulder Rez Marathon?

The time limit for the Boulder Rez Marathon is 6.75 hours.

What will the weather be like for the 2026 Boulder Rez Marathon?

The forecast calls for a high of 79°F and a low of 59°F with a 100% chance of rain. Check our detailed hourly forecast above for the best marathon race plan.

Historical Weather

Based on 10 years of data

Avg Temp

62°F

L:54° H:69°

RunScore

Conditions

Rain Freq

0 of 10 yrs

Wind2mph

Dew47°F

Temperature History

Range of temperatures during race hours for each year.

Detailed History

Year	Low / High	Rain	Dew Point
2026 Boulder Rez Marathon Becoming cloudy in the afternoon with late afternoon rain. 2026	60°/77°	-	57°
2025 Boulder Rez Marathon Clear conditions throughout the day with late afternoon rain. 2025	54°/79°	-	49°
2024 Boulder Rez Marathon Clear conditions throughout the day. 2024	63°/87°	-	44°
2023 Boulder Rez Marathon Partly cloudy throughout the day. 2023	64°/76°	-	52°
2022 Boulder Rez Marathon Partly cloudy throughout the day with late afternoon rain. 2022	67°/80°	-	54°
2021 Boulder Rez Marathon Clear conditions throughout the day. 2021	61°/79°	-	55°
2019 Boulder Rez Marathon Partly cloudy throughout the day with late afternoon rain. 2019	54°/66°	-	46°
2018 Boulder Rez Marathon Partly cloudy throughout the day with late afternoon rain. 2018	38°/44°	-	37°
2017 Boulder Rez Marathon Clear conditions throughout the day. 2017	29°/46°	-	30°
2015 Boulder Rez Marathon Cloudy skies throughout the day. 2015	47°/52°	-	48°

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