Illiopolis Weather Forecast

    • 49
    • 74

    Sunny

    • 56
    • 78

    Sunny

    • 53
    • 82

    Mostly Sunny

    • 52
    • 79

    Mostly Sunny

    • 54
    • 79

    Mostly Sunny

    • 59
    • 82

    Mostly Sunny

Today 5 Oct Sangamon

Sunny. Highs in the mid 70s. Northeast Winds around 5 Mph.

Tonight 5 Oct Sangamon

Clear. Lows in the upper 40s. East Winds around 5 Mph.

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Illiopolis Temperature Statistics

October Temperature

Decatur Airport (19.3 miles)

  • Lowest 3 October, 2026

    42.1 °F

  • Average October

    65.1 °F

  • Highest 1 October, 2026

    88.6 °F

Climate (2021–2026)

Decatur Airport (19.3 miles)

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  • Average Low 2021–2026

    45.4 °F

  • Average 2021–2026

    55.6 °F

  • Average High 2021–2026

    65.6 °F
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