Winchester weather by month
What a typical year looks like in Winchester, California: average highs and lows, rain and snow, and the warmest and coldest days on record. Normals are the 1991–2020 averages at SAN JACINTO, 13 km from Winchester; records cover 1978–2026.
The year at a glance
- Precipitation a year
- 12.2 in310 mm
- Snow a year
- Rare
- Last spring freeze
- Feb 16
- First fall freeze
- Dec 7
- Heating degree days
- 1,801
- Cooling degree days
- 1,810
Freeze dates are medians (half of years earlier, half later). Degree days use a 65°F base; HVAC design temperatures here are 29°−2° (heating, 99%) and 108°42° (cooling, 1%).
Month by month
Winchester in January
Highs average 66°19° and lows 40°5°, with 2.7 in68 mm of precipitation in a typical January.
- Record high
- 91°33° (2003)
- Record low
- 20°−7° (2007)
- Heating degree days
- 374
- Cooling degree days
- 0
Winchester in February
Highs average 66°19° and lows 42°5°, with 2.8 in70 mm of precipitation in a typical February.
- Record high
- 91°33° (2014)
- Record low
- 24°−4° (1985)
- Heating degree days
- 316
- Cooling degree days
- 1
Winchester in March
Highs average 70°21° and lows 45°7°, with 1.7 in43 mm of precipitation in a typical March.
- Record high
- 102°39° (2026)
- Record low
- 26°−3° (1988)
- Heating degree days
- 238
- Cooling degree days
- 9
Winchester in April
Highs average 74°24° and lows 48°9°, with 0.79 in20 mm of precipitation in a typical April.
- Record high
- 103°39° (1989)
- Record low
- 31°−1° (1982)
- Heating degree days
- 145
- Cooling degree days
- 30
Winchester in May
Highs average 80°27° and lows 53°12°, with 0.47 in12 mm of precipitation in a typical May.
- Record high
- 110°43° (1984)
- Record low
- 36°2° (1989)
- Heating degree days
- 57
- Cooling degree days
- 115
Winchester in June
Highs average 89°32° and lows 58°14°, with 0.07 in1.8 mm of precipitation in a typical June.
- Record high
- 114°46° (1985)
- Record low
- 40°4° (2001)
- Heating degree days
- 7
- Cooling degree days
- 252
Winchester in July
Highs average 95°35° and lows 64°18°, with 0.2 in5.1 mm of precipitation in a typical July.
- Record high
- 115°46° (1995)
- Record low
- 46°8° (1993)
- Heating degree days
- 0
- Cooling degree days
- 445
Winchester in August
Highs average 97°36° and lows 64°18°, with 0.12 in3 mm of precipitation in a typical August.
- Record high
- 115°46° (1985)
- Record low
- 44°7° (1978)
- Heating degree days
- 0
- Cooling degree days
- 477
Winchester in September
Highs average 92°33° and lows 61°16°, with 0.26 in6.6 mm of precipitation in a typical September.
- Record high
- 116°47° (1982)
- Record low
- 35°2° (1989)
- Heating degree days
- 3
- Cooling degree days
- 340
Winchester in OctoberThis month
Highs average 82°28° and lows 53°12°, with 0.54 in14 mm of precipitation in a typical October.
- Record high
- 109°43° (2024)
- Record low
- 31°−1° (2003)
- Heating degree days
- 47
- Cooling degree days
- 124
Winchester in November
Highs average 73°23° and lows 44°7°, with 0.77 in20 mm of precipitation in a typical November.
- Record high
- 96°36° (2010)
- Record low
- 25°−4° (1979)
- Heating degree days
- 211
- Cooling degree days
- 17
Winchester in December
Highs average 65°18° and lows 39°4°, with 1.9 in47 mm of precipitation in a typical December.
- Record high
- 90°32° (1979)
- Record low
- 18°−8° (1978)
- Heating degree days
- 403
- Cooling degree days
- 0