Crystal Lake Weather Forecast

    • 63
    • 85

    Mostly Sunny

    • 62
    • 86

    Slight Chance Thunderstorms

    • 54
    • 76

    Partly Sunny

    • 58
    • 71

    Rain Showers Likely

    • 57
    • 81

    Chance Thunderstorms

    • 52
    • 68

    Chance Rain Showers

    • 54
    • 66

    Chance Rain Showers

Today 10 Sep Dakota

Sunny. Near steady temperature in the upper 70s. South Winds 5 to 10 Mph with Gusts up to 20 Mph.

Tonight 10 Sep Dakota

Clear. Not as cool with Lows in the lower 60s. South Winds 10 to 15 Mph with Gusts up to 25 Mph.

Graph Plots Open in Graphs

  • Temperature Forecast NOAA

  • Temperature Real-Time

Crystal Lake Temperature Statistics

September Temperature

Sioux City, Sioux Gateway Airport (5 miles)

  • Lowest 1 September, 2026

    67.6 °F

  • Average September

    79.1 °F

  • Highest 3 September, 2026

    93.7 °F

Climate (2021–2026)

Sioux City, Sioux Gateway Airport (5 miles)

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

  • Average Low 2021–2026

    39.1 °F

  • Average 2021–2026

    51.3 °F

  • Average High 2021–2026

    63.5 °F
Get WillyWeather+ to remove ads