The highest day temperature in January 2026 was 53°F. The lowest night temperature was -16°F. The average values for day and night temperatures during January were 22.2°F и 14.8°F respectivly.

Most of the days in January are gloomy but you can also expect sunny days.

Precipitation total in January for Naperville is 0.9 in.

The average wind speed in January is 9.0 mph.

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 January is 3.8 hours.