Big Sky Marathon

Ennis, MT, USA · July 12, 2026
clear-day59°·80° high·Breezy·Dry
8
Weather
Pace Calc
Course
Race Info
FAQ
History

Race Day Weather

clear-day
59°at start
81° high
Breezy
Dry

Warm afternoon, moderate winds

Runners will face a temperature rise from 53°F at the start to 81°F by the finish, with average humidity at 43%. Winds will be from the SW at 10 mph, gusting to 25 mph. Runners should consider pacing conservatively early and hydrate frequently to manage the warming conditions.

Race day forecast available in 64 days
clear-night9
clear-day9
clear-day9
clear-day9
clear-day8
clear-day8
clear-day8
clear-day8
clear-day7
clear-day7
partly-cloudy-day7

Pace Calculator

Distance: 26.2mi
0:00:00
HH:MM:SS
Pace
—
Weather Adj.
—
Common Goals:

Get forecast alerts for Big Sky Marathon

We'll text or email you when the forecast shifts — so you can adjust gear, pacing, and strategy. Max one per day.

Race Info

The Big Sky Marathon offers runners a thrilling point-to-point course through Montana's high mountains, starting at approximately 8,600 feet elevation and descending into the charming town of Ennis. This trail marathon is part of the Greater Yellowstone Adventure Series and features stunning mountain views throughout the challenging downhill route. The race is known as one of the longest downhill road marathons on the planet, making it a bucket list event for serious runners.

Website
Area Map

Course Map

Course Map Unavailable

We don't have course map data for Big Sky Marathon yet. If you have a GPX file (or other format) for this race, we'd love to add it!

FAQ

Ask a Question about the Big Sky Marathon

Racecast Concierge (free during beta)

Ask a question about the Big Sky 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 Big Sky Marathon and general racecast.io updates.

When is the 2026 Big Sky Marathon?

The 2026 Big Sky Marathon will be held on Sunday July 12, 2026.

What will the weather be like for the 2026 Big Sky Marathon?

The forecast calls for a high of 81°F and a low of 51°F with a 0% chance of rain.

Historical Weather

Based on 2 years of data
Avg Temp
87°F
L:55° H:87°
RunScore
7
Conditions
Rain Freq
0%
0 of 2 yrs
Wind10mph
Dew34°F

Temperature History

Range of temperatures during race hours for each year.

Detailed History

YearConditionsLow / HighRainScore

2025 Big Sky Marathon

Clear conditions throughout the day.

2025
clear-day
55°/86°-
8

2024 Big Sky Marathon

Clear conditions throughout the day.

2024
clear-day
56°/89°-
8

More MT Races

Bob Marshall Trail Half Marathon, 50K, and 10K
2026-07-18 · Seeley Lake, MT, USA
Whitefish Marathon
2026-05-16 · Whitefish, MT, USA
Beaverhead Marathon
2026-05-23 · Dillon, MT, USA
Governors Cup Marathon
2026-06-13 · Helena, MT, USA
Missoula Marathon
2026-06-28 · Missoula, MT, USA
Madison Marathon (MT)
2026-07-11 · Ennis, MT, USA
Free guidesMarathon Fueling Guide·Carb Loading Guide·Race Morning Guide·Race Day Gear Guide·Pacing Strategy Guide·Mental Strategy Guide

Race Day Alerts

Get notified when the Big Sky Marathon forecast shifts — so you can adjust your gear, pacing, and strategy.

Forecast shift alerts (temp, wind, rain)
Updates as weather changes leading up to race day
Max one message per day
Text Alerts

USA, UK, and Canada only. Standard rates apply.

or
Email Alerts

By subscribing you agree to receive race forecasts and racecast.io updates.

Submit a correction

Spot something wrong or missing for the Big Sky Marathon? Let us know and we'll update it.

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

Submit a race

Missing a race? Send it in and we'll add it to Racecast.