The highest day temperature in July 2025 was 100°F. The lowest night temperature was 61°F. The average values for day and night temperatures during July were 89.6°F и 71.8°F respectivly.

You can expect various weather conditions during July. Be ready for sunny, cloudy or even gloomy days.

Precipitation total in July for Naperville is 1.2 in. It makes july one of the most rainy months of the year.

The average wind speed in July is 6.6 mph. It makes July the most windless month of the year for Naperville.

We are using day length and cloud cover information for each day of the month to calculate averages for this chart. Average sunny hours for Naperville in July is 8.8 hours.