Weather forecast for: Bethalto IL
Last Update: 3:31 am CDT Sep 4, 2026
Overnight: Mostly clear, with a low around 76. Light south wind.
Friday: Sunny and hot, with a high near 99. Heat index values as high as 105. Calm wind becoming west around 6 mph in the morning.
Friday Night: Partly cloudy, with a low around 75. Light and variable wind.
Saturday: Mostly sunny and hot, with a high near 99. Heat index values as high as 105. Calm wind becoming west around 6 mph in the morning.
Saturday Night: Mostly clear, with a low around 72. North wind around 5 mph becoming calm.
Sunday: Sunny, with a high near 93.
Sunday Night: Mostly clear, with a low around 67.
Labor Day: Sunny, with a high near 92.
Monday Night: Mostly clear, with a low around 67.
Tuesday: Sunny and hot, with a high near 97.
Tuesday Night: Mostly clear, with a low around 75.
Wednesday: Sunny and hot, with a high near 99.
Wednesday Night: A 20 percent chance of showers and thunderstorms. Mostly clear, with a low around 75.
Thursday: A 20 percent chance of showers and thunderstorms. Mostly sunny, with a high near 95.