Climate Insights for Cook County Airport

The climate in Cook County Airport is warm and mild. The average annual temperature is 21°C and approximately 1046mm of precipitation falls per year. Cook County Airport receives a notable amount of rainfall throughout the year, including during its driest month. Cook County Airport is in the Northern Hemisphere. Summer begins at the end of June and lasts through September. The summer months are: July, August, June. The coldest months are January, December, February, when temperatures can drop to 6°C.

Temperatures in Cook County Airport vary considerably across the year, with a 28°C difference between the coldest and warmest months. The warmest month is July, when average highs reach 34°C and the mean temperature sits around 28°C. January is the coolest month, with minimum temperatures around 6°C and an average of 11°C. On average, daily temperatures fluctuate by about 11°C between overnight lows and afternoon highs. The sharpest temperature change occurs between October and November, with a 5°C shift in average temperatures.

Cook County Airport is a moderately rainy area, receiving approximately 1046mm of precipitation annually, which averages out to around 87mm per month. The wettest month is September, averaging 113mm of rainfall. August and July also tend to see above-average precipitation. The driest month is October, with just 48mm. That's 65mm less than September, the wettest month. Rainfall is relatively evenly distributed throughout the year, so there is no pronounced dry or wet season to plan around.

Cook County Airport is mildly breezy, with an average annual wind speed of 16km/h. For context, sustained winds below 12km/h are generally light, while anything above 25km/h is considered strong. The windiest month is February, averaging 19km/h, though still comfortable for most outdoor activities. The calmest conditions occur in July, with average winds dropping to 14km/h, making it an ideal period for wind-sensitive activities. Wind conditions are fairly consistent throughout the year, varying by only 5km/h between the calmest and windiest months. Wind tends to be stronger during winter months, driven by seasonal pressure systems. The seasonal averages break down to 18km/h in winter, 18km/h in spring, 14km/h in summer, 16km/h in autumn.

It is currently spring in Cook County Airport, which began on March 20, 2026. Cook County Airport is in the Northern Hemisphere, where spring begins in March, summer in June, autumn in September, and winter in December. The warmest period peaks in July at around 34°C, while the coldest stretch bottoms out in January near 6°C. Summer is next, beginning on June 21, 2026 — 89 days from now.

The best time to visit Cook County Airport is during March, April, May, October and November, when the weather is most comfortable for travellers. During these months, average temperatures hover around 20°C with modest rainfall averaging 67mm per month. By contrast, July can be uncomfortably hot with highs reaching 34°C, while January is the coldest period with lows dropping to 6°C. A light rain jacket is recommended, though showers are generally brief and shouldn't disrupt your plans.

The table below shows monthly climate averages for Cook County Airport based on historical weather data. Min and max temperatures represent typical overnight lows and afternoon highs for each month, shown in degrees Celsius (°C). Precipitation is measured in millimetres (mm) and indicates the average total rainfall per month. Wind speed is the average sustained speed in kilometres per hour (km/h). All values are based on averages from over 10 years of historical weather data. The current month is highlighted for quick reference.