December weather in St. Helena, CA
The average temperature in St. Helena in December is 48.9°F (39.6°F–58.3°F). Average precipitation: 7.18 inches.
December is a winter month in St. Helena, and is cooler than the annual average of 61°F. Daily temperatures swing about 18.7°F between overnight low and afternoon high. Expect about 13 days with precipitation. Daylight averages about 9h 19m. For travel, December is a wet month.
Avg High
58.3°F
Avg Low
39.6°F
Precipitation
7.18 in
Daylight
9h 19m
December records in St. Helena
| Date | Record High | Record Low | Record Precip |
|---|---|---|---|
| December 1 | 79.0°F (1959) | 19.0°F (2020) | 4.16 in (1952) |
| December 2 | 77.0°F (1958) | 25.0°F (1936) | 5.50 in (1980) |
| December 3 | 80.1°F (1958) | 21.9°F (1936) | 4.11 in (1950) |
| December 4 | 77.0°F (1939) | 21.0°F (1936) | 3.76 in (1970) |
| December 5 | 80.1°F (1929) | 21.9°F (1972) | 2.00 in (1909) |
| December 6 | 80.1°F (1925) | 24.1°F (2013) | 1.39 in (1955) |
| December 7 | 75.0°F (1925) | 21.0°F (1919) | 3.60 in (1952) |
| December 8 | 75.9°F (1943) | 21.0°F (1972) | 3.24 in (1992) |
| December 9 | 75.9°F (1940) | 17.1°F (1972) | 3.01 in (1909) |
| December 10 | 77.0°F (1958) | 15.1°F (1932) | 4.42 in (1937) |
| December 11 | 78.1°F (1958) | 10.9°F (1932) | 5.45 in (2014) |
| December 12 | 82.0°F (1958) | 23.0°F (1972) | 5.30 in (1995) |
| December 13 | 75.0°F (1910) | 19.9°F (1932) | 4.00 in (2002) |
| December 14 | 77.0°F (1958) | 18.0°F (1919) | 4.20 in (2002) |
| December 15 | 81.0°F (1980) | 18.0°F (1932) | 3.02 in (1929) |
| December 16 | 75.9°F (1980) | 21.0°F (1919) | 3.00 in (2002) |
| December 17 | 81.0°F (1998) | 19.9°F (1919) | 1.83 in (1962) |
| December 18 | 75.0°F (1958) | 19.9°F (1924) | 3.36 in (1940) |
| December 19 | 71.1°F (1937) | 18.0°F (1924) | 5.76 in (1955) |
| December 20 | 70.0°F (1929) | 21.9°F (1990) | 4.10 in (1981) |
| December 21 | 70.0°F (1922) | 14.0°F (1990) | 4.02 in (1964) |
| December 22 | 73.0°F (1914) | 16.0°F (1990) | 4.94 in (1955) |
| December 23 | 73.9°F (1938) | 19.9°F (1990) | 3.05 in (1955) |
| December 24 | 75.0°F (2013) | 18.0°F (1930) | 3.41 in (1913) |
| December 25 | 75.9°F (1972) | 21.0°F (1990) | 2.68 in (1940) |
| December 26 | 79.0°F (1967) | 19.9°F (1924) | 2.42 in (1955) |
| December 27 | 82.9°F (1967) | 23.0°F (1962) | 3.53 in (1931) |
| December 28 | 77.0°F (1975) | 21.9°F (1930) | 2.40 in (2002) |
| December 29 | 73.9°F (1997) | 21.9°F (1930) | 2.20 in (2003) |
| December 30 | 73.9°F (1997) | 21.0°F (1930) | 7.00 in (1913) |
| December 31 | 70.0°F (1997) | 21.0°F (1915) | 5.26 in (2005) |