Monday, October 19, 2026 · Hour-by-hour forecast updated 2:12 AM CDT
57°F and clear at peak. Wind 5 mph from the SW, dew point 46°F.
Running in Chicago peaks twice a year — May (FitScore 81) and October (80) — with typical morning lows of 50°F and 49°F respectively. January is the limiting month, with average lows of 20°F pulling its FitScore down to 44. Across the full year, Chicago ranks #176 of 200 U.S. running cities, with an annual FitScore of 67 (national median: 74). 5 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 Chicago are May, October, and June, with average FitScores of 81, 80, and 76 based on a decade of daily weather history. The most challenging is January (FitScore 44). Lakefront trail gets breezy — run along the water for natural cooling.
Historically, October in Chicago averages a FitScore of 80/100 — excellent running weather — with highs around 62°F, lows around 49°F, dew points near 46°F, and 9.2 days of measurable rain. That's below 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.