Jamestown weather by month
What a typical year looks like in Jamestown, California: average highs and lows, rain and snow, and the warmest and coldest days on record. Normals are the 1991–2020 averages at Sonora, 2 km from Jamestown; records cover 1906–2026.
The year at a glance
- Precipitation a year
- 32.8 in833 mm
- Snow a year
- Rare
- Last spring freeze
- Apr 14
- First fall freeze
- Nov 5
- Heating degree days
- 3,573
- Cooling degree days
- 928
Freeze dates are medians (half of years earlier, half later). Degree days use a 65°F base; HVAC design temperatures here are 24°−4° (heating, 99%) and 102°39° (cooling, 1%).
Month by month
Jamestown in January
Highs average 56°13° and lows 33°0°, with 6.3 in161 mm of precipitation in a typical January.
- Record high
- 75°24° (1953)
- Record low
- 13°−11° (1949)
- Heating degree days
- 643
- Cooling degree days
- 0
Jamestown in February
Highs average 58°15° and lows 34°1°, with 5.5 in140 mm of precipitation in a typical February.
- Record high
- 78°26° (1943)
- Record low
- 15°−9° (1989)
- Heating degree days
- 526
- Cooling degree days
- 0
Jamestown in March
Highs average 62°17° and lows 37°3°, with 5.4 in136 mm of precipitation in a typical March.
- Record high
- 87°31° (2026)
- Record low
- 20°−7° (1951)
- Heating degree days
- 479
- Cooling degree days
- 0
Jamestown in April
Highs average 67°19° and lows 40°4°, with 3 in77 mm of precipitation in a typical April.
- Record high
- 92°33° (1987)
- Record low
- 24°−4° (1963)
- Heating degree days
- 356
- Cooling degree days
- 2
Jamestown in May
Highs average 76°24° and lows 46°8°, with 1.5 in39 mm of precipitation in a typical May.
- Record high
- 103°39° (1984)
- Record low
- 24°−4° (1961)
- Heating degree days
- 174
- Cooling degree days
- 36
Jamestown in June
Highs average 85°30° and lows 51°10°, with 0.34 in8.6 mm of precipitation in a typical June.
- Record high
- 113°45° (1961)
- Record low
- 34°1° (1939)
- Heating degree days
- 45
- Cooling degree days
- 137
Jamestown in July
Highs average 93°34° and lows 57°14°, with 0.03 in0.8 mm of precipitation in a typical July.
- Record high
- 113°45° (1972)
- Record low
- 35°2° (2026)
- Heating degree days
- 2
- Cooling degree days
- 306
Jamestown in August
Highs average 92°33° and lows 56°13°, with 0.07 in1.8 mm of precipitation in a typical August.
- Record high
- 110°43° (1933)
- Record low
- 38°3° (1985)
- Heating degree days
- 2
- Cooling degree days
- 272
Jamestown in September
Highs average 87°30° and lows 51°10°, with 0.2 in5.1 mm of precipitation in a typical September.
- Record high
- 110°43° (2022)
- Record low
- 33°1° (2026)
- Heating degree days
- 36
- Cooling degree days
- 148
Jamestown in OctoberThis month
Highs average 76°25° and lows 43°6°, with 1.6 in42 mm of precipitation in a typical October.
- Record high
- 100°38° (1980)
- Record low
- 25°−4° (1971)
- Heating degree days
- 195
- Cooling degree days
- 27
Jamestown in November
Highs average 63°17° and lows 36°2°, with 3.2 in82 mm of precipitation in a typical November.
- Record high
- 89°32° (1966)
- Record low
- 21°−6° (1975)
- Heating degree days
- 456
- Cooling degree days
- 0
Jamestown in December
Highs average 55°13° and lows 32°0°, with 5.5 in140 mm of precipitation in a typical December.
- Record high
- 81°27° (1958)
- Record low
- 8°−13° (1972)
- Heating degree days
- 659
- Cooling degree days
- 0