The 2025 event has concluded.

Diablo Trail Marathon

Clayton, CA, USA • September 7, 2025
TopDescriptionCourseCommunity
Register

Subscribe

Get updates on the Diablo Trail Marathon race forecast and be the first to know if the forecast shifts.

Text Updates

Maximum one update per day. Standard messaging rates apply. Currently only supports USA, UK, and Canada.

Phone Number

Email Updates

By submitting your email you agree to receive weather forecasts and racecast.io updates.

clear-day Clear conditions throughout the day.

That OG frictionless feeling. Body Glide Original Anti-Chafe Balm.When you buy through our links, we may earn a commission.

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

Area Map

Course Maps

FAQ

Ask a Question about the Diablo Trail Marathon

Racecast Concierge (free during beta)

Ask a question about the Diablo Trail 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 Diablo Trail Marathon and general racecast.io updates.

When is the 2025 Diablo Trail Marathon?

The 2025 Diablo Trail Marathon will be held on Sunday September 7, 2025.

Community

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

Historical Weather & Results

RunScore
Run Score: 6
Temp
85°F
Min/Max
61°/85°F
Dew
47°F
Days of Rain
2/12
Wind
11mph
Tap a row for details.
YearLow / HighRain

Diablo Trail Marathon 2024 Weather History

Clear conditions throughout the day.

2024
clear-day
60°/ 94°-
Run Score: 8

Diablo Trail Marathon 2023 Weather History

Clear conditions throughout the day.

2023
clear-day
58°/ 87°-
Run Score: 8

Diablo Trail Marathon 2022 Weather History

Partly cloudy throughout the day with rain.

2022
rain
63°/ 72°Light
Run Score: 7

Diablo Trail Marathon 2021 Weather History

Clearing in the afternoon.

2021
cloudy
60°/ 81°-
Run Score: 8

Diablo Trail Marathon 2019 Weather History

Clear conditions throughout the day.

2019
clear-day
67°/ 92°-
Run Score: 7

Diablo Trail Marathon 2018 Weather History

Clear conditions throughout the day.

2018
cloudy
58°/ 79°-
Run Score: 8

Diablo Trail Marathon 2017 Weather History

Clear conditions throughout the day.

2017
clear-day
68°/ 103°-
Run Score: 6

Diablo Trail Marathon 2016 Weather History

Clearing in the afternoon.

2016
cloudy
61°/ 82°-
Run Score: 8

Diablo Trail Marathon 2015 Weather History

Clear conditions throughout the day with afternoon rain.

2015
partly-cloudy-day
65°/ 83°Light
Run Score: 7

Diablo Trail Marathon 2014 Weather History

Clear conditions throughout the day.

2014
cloudy
58°/ 82°-
Run Score: 8

Diablo Trail Marathon 2013 Weather History

Clear conditions throughout the day.

2013
clear-day
56°/ 81°-
Run Score: 8

Diablo Trail Marathon 2012 Weather History

Clear conditions throughout the day.

2012
clear-day
54°/ 82°-
Run Score: 8
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
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