Merriam Lake Weather Forecast
- 35
- 45
Rain Showers Likely
- 33
- 39
Rain Showers Likely
- 34
- 45
Slight Chance Thunderstorms
- 35
- 46
Partly Sunny
- 37
- 49
Partly Sunny
- 35
- 47
Chance Rain
Today 18 Sep Upper San Joaquin River
Cloudy. Chance of rain in the late morning and early afternoon. Rain Showers likely and slight chance of Thunderstorms late in the afternoon. Some Thunderstorms may produce heavy rainfall late in the afternoon. Highs 53 to 69. Southeast Winds up to 10 Mph. Chance of precipitation 60 percent.
Tonight 18 Sep Upper San Joaquin River
Colder. Rain Showers likely and slight chance of Thunderstorms. Some Thunderstorms may produce heavy rainfall. Lows 39 to 49. Southeast Winds up to 10 Mph. Chance of precipitation 60 percent.
Merriam Lake Temperature Statistics
September Temperature
Mammoth Yosemite Airport (22.4 miles)
Lowest 7 September, 2025
35.6 °FAverage September
57.5 °FHighest 1 September, 2025
80.6 °F
Climate (2020–Present)
Mammoth Yosemite Airport (22.4 miles)
Average Low 2020–2025
29.7 °FAverage 2020–2025
46.2 °FAverage High 2020–2025
61 °F