Lake Merwin Weather Forecast

    • 44
    • 53

    Mostly Cloudy

    • 45
    • 57

    Rain

    • 48
    • 51

    Rain

    • 46
    • 53

    Rain

    • 39
    • 49

    Rain

    • 39
    • 41

    Rain

Today 12 Dec South Washington Cascade Foothills

Mostly cloudy. Patchy fog. Highs in the upper 50s. Winds light.

Tonight 12 Dec South Washington Cascade Foothills

Mostly cloudy in the Evening, then becoming partly cloudy. Patchy dense fog. Lows in the lower 40s. Winds light.

Graph Plots Open in Graphs

  • Temperature Forecast NOAA

  • Temperature Real-Time

Lake Merwin Temperature Statistics

December Temperature

Southwest Washington Regional Airport (22.4 miles)

  • Lowest 1 December, 2025

    35.1 °F

  • Average December

    48.4 °F

  • Highest 10 December, 2025

    57.9 °F

Climate (2020–Present)

Southwest Washington Regional Airport (22.4 miles)

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

  • Average Low 2020–2025

    45.1 °F

  • Average 2020–2025

    52.9 °F

  • Average High 2020–2025

    62.4 °F
Get WillyWeather+ to remove ads