Tuesday, July 21, 2026 · Hour-by-hour forecast updated 8:24 AM CDT
61°F and clear at peak. Wind 7 mph from the N, dew point 50°F.
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 5 AM–9 AM with a peak FitScore of 99/100. Check the hourly breakdown above for detailed conditions throughout the day.
The best months for running in Naperville are April, May, September, October. The most challenging months are typically January, February. Summer humidity rivals the Southeast. Watch for fast-moving thunderstorms in the afternoon.
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.