Illiopolis Weather Forecast

    • 63
    • 81

    Rain Showers Likely

    • 65
    • 82

    Slight Chance Thunderstorms

    • 66
    • 84

    Rain Showers

    • 62
    • 78

    Rain Showers

    • 60
    • 81

    Slight Chance Thunderstorms

    • 61
    • 86

    Rain Showers Likely

    • 42
    • 77

    Rain Showers Likely

Today 12 Apr Sangamon

Mostly cloudy with a chance of Showers with a slight chance of Thunderstorms. Breezy, warmer. Near steady temperature in the upper 70s. South Winds 20 to 25 Mph with Gusts up to 35 Mph. Chance of rain 50 percent.

Tonight 12 Apr Sangamon

Mostly cloudy. Showers likely with a chance of Thunderstorms in the Evening, then a chance of Showers with a slight chance of Thunderstorms after midnight. Breezy with Lows in the lower 60s. Southwest Winds 15 to 25 Mph with Gusts up to 35 Mph. Chance of rain 70 percent.

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  • Temperature Forecast NOAA

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Illiopolis Temperature Statistics

April Temperature

Decatur Airport (19.3 miles)

  • Lowest 7 April, 2026

    34.6 °F

  • Average April

    55.3 °F

  • Highest 3 April, 2026

    79.6 °F

Climate (2021–Present)

Decatur Airport (19.3 miles)

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  • Average Low 2021–2026

    45.3 °F

  • Average 2021–2026

    55.4 °F

  • Average High 2021–2026

    65.4 °F
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