Monday, October 19, 2026 · Hour-by-hour forecast updated 2:12 AM CDT
58°F and clear at peak. Wind 4 mph from the SW, dew point 44°F.
Running in Naperville peaks twice a year — May (FitScore 83) and October (83) — with typical morning lows of 51°F and 47°F respectively. January is the limiting month, with average lows of 18°F pulling its FitScore down to 47. Across the full year, Naperville ranks #159 of 200 U.S. running cities, with an annual FitScore of 70 (national median: 74). 8 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 Naperville are May, October, and April, with average FitScores of 83, 83, and 81 based on a decade of daily weather history. The most challenging is January (FitScore 47).
Historically, October in Naperville averages a FitScore of 83/100 — excellent running weather — with highs around 63°F, lows around 47°F, dew points near 44°F, and 8.7 days of measurable rain. That's about even with 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.