Diablo Trail Marathon
Clayton, CA, USA • September 6, 2026
Race Day Weather
61°
89° high
Breezy
Dry
Warm day, adjust pace accordingly
Runners will face a temperature rising from 64°F to a peak of 89°F, with average humidity at 44% and a dew point of 51°F. A steady SW wind at 12 mph will provide some cooling but may also challenge pacing. Runners should start conservatively and adjust their pace as temperatures climb, ensuring proper hydration throughout.
Race day forecast available in 153 days
Pre-raceRace windowPost-race
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
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 | Conditions | Low / High | Rain | Dew Point | Score |
|---|---|---|---|---|---|
2025 | | 64°/82° | - | 55° | |
2024 | | 60°/94° | - | 50° | |
2023 | | 58°/87° | - | 53° | |
2022 |  | 63°/72° | Light | 55° | |
2021 |  | 60°/81° | - | 54° | |
2019 | | 67°/92° | - | 57° | |
2018 | | 58°/79° | - | 51° | |
2017 | | 68°/103° | - | 54° | |
2016 | | 61°/82° | - | 52° | |
2015 |  | 65°/83° | Light | 53° | |
2014 | | 58°/82° | - | 52° | |
2013 | | 56°/81° | - | 25° | |
2012 | | 54°/82° | - | 50° |
More CA Races
San Lorenzo River Marathon
2026-07-11 · Santa Cruz, CA, USA
Wild West Marathon & Ultra
2026-05-02 · Lone Pine, CA, USA
Golden Gate Trail Run Marathon
2027-02-06 · Rodeo Beach, CA, USA
Griffith Park Trail Marathon
2026-03-28 · Los Angeles, CA, USA
Carlsbad 5000
2026-04-12 · Carlsbad, CA, USA
Saddleback Marathon
2026-11-07 · Lake Elsinore, CA, USA