Illiopolis Weather Forecast

    • 55
    • 64

    Mostly Cloudy

    • 63
    • 81

    Partly Sunny

    • 45
    • 82

    Rain Showers

    • 46
    • 53

    Rain Showers

    • 44
    • 64

    Rain Showers Likely

    • 53
    • 70

    Rain Showers Likely

    • 45
    • 70

    Rain Showers Likely

Today 29 Mar Sangamon

Cloudy and not as cool. Near steady temperature in the lower 60s. South Winds around 15 Mph with Gusts up to 25 Mph.

Tonight 29 Mar Sangamon

Mostly cloudy. Not as cool with Lows in the mid 50s. South Winds 10 to 15 Mph with Gusts up to 25 Mph.

Graph Plots Open in Graphs

  • Temperature Forecast NOAA

  • Temperature Real-Time

Illiopolis Temperature Statistics

March Temperature

Decatur Airport (19.3 miles)

  • Lowest 17 March, 2026

    14.6 °F

  • Average March

    48.7 °F

  • Highest 26 March, 2026

    88 °F

Climate (2021–Present)

Decatur Airport (19.3 miles)

Take a look at our website widgetsAvailable free! Find Out More

  • Average Low 2021–2026

    45.3 °F

  • Average 2021–2026

    55.4 °F

  • Average High 2021–2026

    65.4 °F
Get WillyWeather+ to remove ads