Grinnell Lake Weather Forecast
- 18
- 31
Partly Sunny
- 22
- 39
Mostly Sunny
- 24
- 45
Mostly Sunny
- 24
- 44
Mostly Sunny
- 25
- 44
Partly Sunny
- 26
- 44
Partly Sunny
- 24
- 41
Partly Sunny
Today 23 Oct Upper San Joaquin River
Not as cool. Mostly sunny. Slight chance of rain and snow early in the afternoon. Slight chance of snow late in the afternoon. Highs 33 to 49. North Winds up to 10 Mph. Gusts up to 25 Mph in the afternoon. Chance of precipitation 20 percent.
Tonight 23 Oct Upper San Joaquin River
Mostly clear. Lows 22 to 34. Northeast Winds 10 to 15 Mph with Gusts to around 50 Mph.
Grinnell Lake Temperature Statistics
October Temperature
Mammoth Yosemite Airport (10.6 miles)
Lowest 18 October, 2026
23 °FAverage October
51.8 °FHighest 1 October, 2026
78.8 °F
Climate (2021–2026)
Mammoth Yosemite Airport (10.6 miles)
Average Low 2021–2026
29.5 °FAverage 2021–2026
45.8 °FAverage High 2021–2026
60.6 °F