Six Flags - Great America Weather Forecast
- 72
- 84
Decreasing Clouds
- 78
- 93
Partly Sunny
- 71
- 94
Thunderstorms Likely
- 69
- 81
Chance Thunderstorms
- 70
- 85
Slight Chance Thunderstorms
- 71
- 88
Mostly Sunny
Today 22 Jul Lake
Partly cloudy late in the Morning, then becoming mostly sunny. Highs in the mid 80s Inland, but only in the lower 80s near the lake. Southeast Winds 5 to 10 Mph.
Tonight 22 Jul Lake
Mostly clear in the Evening, then becoming partly cloudy. Lows in the lower 70s. Southeast Winds 5 to 10 Mph.
Six Flags - Great America Temperature Statistics
July Temperature
Chicago/Waukegan Regional Airport (5 miles)
Lowest 17 July, 2025
55.7 °FAverage July
74.8 °FHighest 5 July, 2025
93.7 °F
Climate (2020–Present)
Chicago/Waukegan Regional Airport (5 miles)
Average Low 2020–2025
42.2 °FAverage 2020–2025
51 °FAverage High 2020–2025
59.5 °F