Rainier Weather Forecast

    • 62
    • 84

    Decreasing Clouds

    • 63
    • 83

    Slight Chance Thunderstorms

    • 61
    • 76

    Chance Thunderstorms

    • 60
    • 75

    Mostly Cloudy

    • 59
    • 72

    Chance Rain Showers

    • 58
    • 70

    Chance Rain Showers

Today 4 Sep Lower Columbia River

Sunny, hazy. Areas of smoke in the afternoon. Highs around 90. Winds light.

Tonight 4 Sep Lower Columbia River

Mostly clear in the Evening, then becoming partly cloudy. Lows in the lower 60s. Northwest wind 5 to 10 Mph.

Graph Plots Open in Graphs

  • Temperature Forecast NOAA

  • Temperature Real-Time

Rainier Temperature Statistics

September Temperature

Southwest Washington Regional Airport (2.5 miles)

  • Lowest 1 September, 2025

    60.1 °F

  • Average September

    65.9 °F

  • Highest 1 September, 2025

    77 °F

Climate (2020–Present)

Southwest Washington Regional Airport (2.5 miles)

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

  • Average Low 2020–2025

    45 °F

  • Average 2020–2025

    52.8 °F

  • Average High 2020–2025

    62.3 °F
Get WillyWeather+ to remove ads