Cook County Forest Preserve Weather Forecast
- 58
- 69
Rain Showers
- 55
- 65
Chance Rain Showers
- 54
- 63
Mostly Cloudy
- 54
- 64
Mostly Cloudy
- 54
- 65
Mostly Cloudy
- 54
- 67
Partly Sunny
Today 20 Sep Northern Cook
Cloudy. Patchy fog early in the morning. Showers and a slight chance of Thunderstorms in the morning. A slight chance of Thunderstorms early in the afternoon. A chance of Showers in the afternoon. Some Thunderstorms may produce heavy rainfall in the morning. Breezy. Highs in the upper 60s. Northeast Winds 15 to 20 Mph with Gusts up to 30 Mph. Chance of precipitation 90 percent.
Tonight 20 Sep Northern Cook
Cloudy. A slight chance of Showers after midnight. A chance of Showers late. Lows in the upper 50s. Northeast Winds 15 to 20 Mph with Gusts up to 25 Mph, becoming east 10 to 15 Mph after midnight. Chance of precipitation 30 percent.
Cook County Forest Preserve Temperature Statistics
September Temperature
Chicago, Chicago-O'Hare International Airport (2.5 miles)
Lowest 14 September, 2026
53.7 °FAverage September
75.6 °FHighest 2 September, 2026
96.7 °F
Climate (2021–2026)
Chicago, Chicago-O'Hare International Airport (2.5 miles)
Average Low 2021–2026
45.3 °FAverage 2021–2026
53.6 °FAverage High 2021–2026
61.9 °F