Monday, October 19, 2026 · Hour-by-hour forecast updated 1:13 AM MDT
62°F and clear at peak. Wind 2 mph from the E, dew point 32°F.
Running in Thornton peaks twice a year — September (FitScore 96) and June (93) — with typical morning lows of 53°F and 55°F respectively. January is the limiting month, with average lows of 16°F pulling its FitScore down to 63. Across the full year, Thornton ranks #68 of 200 U.S. running cities, with an annual FitScore of 82 (national median: 74). 9 months of the year score 70 or better.
Based on 2015–2024 daily weather history (Open-Meteo ERA5), scored against 200 U.S. cities. Monthly FitScore reflects each day’s best running window.
FitCast texts you tomorrow's hour-by-hour forecast every evening so you know exactly what to expect before your alarm goes off.
Based on today's FitScore analysis, the best time to run is All day with a peak FitScore of 100/100. Check the hourly breakdown above for detailed conditions throughout the day.
The best months for running in Thornton are September, June, and August, with average FitScores of 96, 93, and 92 based on a decade of daily weather history. The most challenging is January (FitScore 63).
Historically, October in Thornton averages a FitScore of 90/100 — excellent running weather — with highs around 65°F, lows around 39°F, dew points near 29°F, and 2.9 days of measurable rain. That's above the national median of 86 for October.
FitScore rates each hour from 0–100 for outdoor exercise based on temperature, humidity, dew point, wind, precipitation probability, UV index, and air quality. Higher scores mean better conditions.