Ontario Weather Forecast

    • 48
    • 69

    Mostly Sunny

    • 51
    • 81

    Chance Thunderstorms

    • 44
    • 70

    Mostly Sunny

    • 54
    • 72

    Partly Sunny

    • 60
    • 76

    Chance Thunderstorms

    • 61
    • 83

    Slight Chance Thunderstorms

Today 11 May Knox

Sunny. Highs around 70. North Winds 5 to 10 Mph.

Tonight 11 May Knox

Mostly clear. Lows in the upper 40s. Northeast Winds 5 to 10 Mph, becoming southeast with Gusts up to 25 Mph after midnight.

Graph Plots Open in Graphs

  • Temperature Forecast NOAA

  • Temperature Real-Time

Ontario Temperature Statistics

May Temperature

Galesburg Municipal Airport (11.8 miles)

  • Lowest 7 May, 2026

    32.7 °F

  • Average May

    53.3 °F

  • Highest 4 May, 2026

    80.4 °F

Climate (2021–Present)

Galesburg Municipal Airport (11.8 miles)

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

  • Average Low 2021–2026

    41.6 °F

  • Average 2021–2026

    51.9 °F

  • Average High 2021–2026

    62.3 °F
Get WillyWeather+ to remove ads