Oak Brook (IL) Weather & Climate: Best Time to Visit

In Oak Brook, temperatures differ significantly between summer and winter months. Average daytime temperatures reach a comfortable 29°C (84°F) in July. In January, the coolest month of the year, temperatures drop to a very cold 0°C (32°F).

At night, temperatures range from around 18°C (64°F) in July to -9°C (16°F) in January.

Check out our detailed temperature page for more information.

Temperature ranges by month

Oak Brook experiences significant rain/snowfall throughout the year, averaging 1058 mm (42 in) of precipitation annually. Oak Brook can be quite wet during June, receiving approximately 125 mm (4.9 in) of precipitation over 15 rainy days.

In contrast, during the driest month (January), you will experience much drier conditions, with 52 mm (2 in) of precipitation spread across 13 snowy days days. For more details, please visit our Oak Brook Precipitation page.

The mean monthly precipitation over the year, including rain, hail, and snow

The average number of days each month with precipitation

Oak Brook can be enjoyed more throughout the sunniest month of July under a blue sky, with approximately 10.6 hours of sunshine daily. In contrast, the city experiences much darker days in December, with only 3.6 hours of sunlight per day.

Visit our detailed sunshine hours page for more information.

Monthly hours of sunshine

Daily hours of sunshine

Daily percentage of sunshine

The relative humidity is high throughout the year in Oak Brook.

The city experiences its highest humidity in December, reaching 76%. In May, the humidity drops to its lowest level at 64%. What does this mean? Read our detailed page on humidity levels for further details.

Relative humidity over the year

The mean wind speed varies between 4 m/s (8 knots) and 6 m/s (12 knots) throughout the year. It is lowest in June, July, August and September and highest during January, March and April. What does this mean?

The mean monthly wind speed over the year (meters per second)