Issaquah Weather Forecast

    • 52
    • 72

    Increasing Clouds

    • 52
    • 72

    Chance Rain

    • 54
    • 74

    Partly Sunny

    • 56
    • 73

    Mostly Cloudy

    • 54
    • 73

    Partly Sunny

    • 57
    • 80

    Mostly Sunny

    • 57
    • 78

    Chance Rain

Today 4 Sep Eastside

Mostly cloudy in the morning then becoming partly sunny. A chance of Showers in the morning. Highs near 70. Light wind.

Tonight 4 Sep Eastside

Partly cloudy. Lows in the lower to mid 50s. Light wind.

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  • Temperature Real-Time

Issaquah Temperature Statistics

September Temperature

Renton Municipal Airport (8.7 miles)

  • Lowest 2 September, 2026

    55 °F

  • Average September

    61.8 °F

  • Highest 2 September, 2026

    69.1 °F

Climate (2021–2026)

Renton Municipal Airport (8.7 miles)

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  • Average Low 2021–2026

    47.5 °F

  • Average 2021–2026

    54.7 °F

  • Average High 2021–2026

    62.2 °F
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