Grasslands Trail Run Marathon
Race Day Weather
Cool start — fast day potential, big temp swing
A cool 49°F at the start line is ideal for fast times — expect to warm up quickly once you're moving. Temps will climb significantly to 65°F by later miles, so expect fading conditions as the race progresses. Light winds shouldn't be a major factor for pacing.
Pace Calculator
Enter a finish time to see what race day does to it.
Get forecast alerts for Grasslands Trail Run 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 Grasslands Trail Run is held in the Lyndon B. Johnson National Grasslands, more than 20,000 acres managed by the U.S. Forest Service and situated north of Fort Worth. The trails loop among rolling hills and through a mixture of pine and oak grove forests, open fields, and livestock. Run the 100-Mile, 50-Mile, Marathon, Half marathon (Saturday Start) or 15K (Sunday Start) and enjoy the beauty of the Grasslands while sharing the trails with horses and running past cows—don’t let the cows out! Source
