Diablo Trail Marathon

Clayton, CA, USA · September 6, 2026

64°·85° high·Light·Dry

Weather

Course

Race Info

FAQ

History

Race Day Weather

64°at start

87° high

Light

Dry

Warm afternoon, adjust pace wisely

Runners will face a temperature rise from 59°F at the start to a warm 86°F by the finish. With light winds from the W and average humidity at 41%, pacing will be crucial. Runners should consider starting conservatively and hydrating frequently to manage the heat effectively.

Race day forecast available in 6 days

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Race Info

Mount Diablo provides spectacular views of the San Francisco Bay Area and surrounding valleys. The 4 mile course is relatively flat and fast within Mitchell Canyon. The longer events are mountainous and very scenic. Source

Website

Course Map

FAQ

When is the 2026 Diablo Trail Marathon?

The 2026 Diablo Trail Marathon will be held on Sunday September 6, 2026.

What will the weather be like for the 2026 Diablo Trail Marathon?

The forecast calls for a high of 85°F and a low of 58°F with a 0% chance of rain.

Historical Weather

Based on 13 years of data

Avg Temp

85°F

L:61° H:85°

RunScore

Conditions

Rain Freq

15%

2 of 13 yrs

Wind11mph

Dew48°F

Temperature History

Range of temperatures during race hours for each year.

Detailed History

Year	Low / High	Rain	Dew Point
2025 Diablo Trail Marathon Clear conditions throughout the day. 2025	64°/82°	-	55°
2024 Diablo Trail Marathon Clear conditions throughout the day. 2024	60°/94°	-	50°
2023 Diablo Trail Marathon Clear conditions throughout the day. 2023	58°/87°	-	53°
2022 Diablo Trail Marathon Partly cloudy throughout the day with rain. 2022	63°/72°	Light	55°
2021 Diablo Trail Marathon Clearing in the afternoon. 2021	60°/81°	-	54°
2019 Diablo Trail Marathon Clear conditions throughout the day. 2019	67°/92°	-	57°
2018 Diablo Trail Marathon Clear conditions throughout the day. 2018	58°/79°	-	51°
2017 Diablo Trail Marathon Clear conditions throughout the day. 2017	68°/103°	-	54°
2016 Diablo Trail Marathon Clearing in the afternoon. 2016	61°/82°	-	52°
2015 Diablo Trail Marathon Clear conditions throughout the day with afternoon rain. 2015	65°/83°	Light	53°
2014 Diablo Trail Marathon Clear conditions throughout the day. 2014	58°/82°	-	52°
2013 Diablo Trail Marathon Clear conditions throughout the day. 2013	56°/81°	-	25°
2012 Diablo Trail Marathon Clear conditions throughout the day. 2012	54°/82°	-	50°

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