Weather on December 20
Sunnyvale, CA
55 Years of Data
Avg High
58°F
Avg Low
42°F
Warmest
1999
62°F avg
Coldest
1998
39°F avg
About This Date
December 20th in Sunnyvale, CA typically brings cool winter weather, with average highs around 58°F and lows near 42°F. Over 55 years of records, the warmest December 20th was in 1999 (62°F average), while the coldest was 1998 (39°F) — a 23°F range across recorded history. Rain or other precipitation has occurred on about 31% of December 20th dates historically, with the wettest December 20th recording 2.24" of rain. The last decade has been 1.0°F warmer on this date compared to 20-30 years ago.
The last decade has been 1.0°F warmer on this date compared to 20-30 years ago.
Planning for December 20th in Sunnyvale, CA? Bring layers as temperatures can vary throughout the day. Consider bringing rain gear or an umbrella.
Warming Trend
0.4°F per decade on this date
| Year | High | Low | Avg | Precip | Snow |
|---|---|---|---|---|---|
| 2025 | 63° | 61° | 62° | — | — |
| 2024 | 59° | 41° | 50° | — | — |
| 2023 | 60° | 53° | 57° | 1.88" | — |
| 2022 | 58° | 44° | 51° | — | — |
| 2021 | 57° | 38° | 47° | — | — |
| 2020 | 62° | 35° | 49° | — | — |
| 2019 | 65° | 45° | 55° | — | — |
| 2018 | 55° | 45° | 50° | — | — |
| 2017 | 56° | 44° | 50° | 0.15" | — |
| 2016 | 58° | 34° | 46° | — | — |
| 2015 | 54° | 36° | 45° | — | — |
| 2014 | 61° | 55° | 58° | 0.03" | — |
| 2013 | 61° | 38° | 49° | — | — |
| 2012 | 59° | 37° | 48° | — | — |
| 2011 | 63° | 37° | 50° | — | — |
| 2010 | 54° | 49° | 51° | — | — |
| 2009 | 67° | 43° | 55° | 0.05" | — |
| 2008 | 52° | 34° | 43° | — | — |
| 2007 | 56° | 43° | 49° | 0.58" | — |
| 2006 | 53° | 34° | 43° | — | — |
| 2005 | 72° | 50° | 61° | — | — |
| 2004 | 51° | 38° | 44° | 0.03" | — |
| 2003 | 60° | 51° | 56° | 0.71" | — |
| 2002 | 56° | 44° | 50° | 1.3" | — |
| 2001 | 52° | 47° | 49° | 2.24" | — |
| 2000 | 63° | 39° | 51° | — | — |
| 1999warmest | 70° | 55° | 62° | — | — |
| 1998coldest | 44° | 33° | 39° | 0.23" | — |
| 1997 | 59° | 39° | 49° | 0.05" | — |
| 1996 | 57° | 36° | 46° | — | — |
| 1995 | 58° | 47° | 52° | — | — |
| 1994 | 53° | 39° | 46° | — | — |
| 1993 | 50° | 35° | 43° | — | — |
| 1992 | 60° | 41° | 51° | — | — |
| 1991 | 61° | 41° | 51° | — | — |
| 1990 | 46° | 36° | 41° | 0.3" | — |
| 1989 | 56° | 41° | 48° | — | — |
| 1988 | 54° | 44° | 49° | 2.08" | — |
| 1987 | 56° | 37° | 46° | — | — |
| 1986 | 60° | 45° | 52° | — | — |
| 1985 | 61° | 39° | 50° | — | — |
| 1984 | 57° | 39° | 48° | — | — |
| 1983 | 53° | 44° | 49° | — | — |
| 1982 | 60° | 51° | 56° | 0.25" | — |
| 1981 | 65° | 54° | 59° | 0.46" | — |
| 1980 | 64° | 43° | 53° | — | — |
| 1979 | 57° | 45° | 51° | 0.41" | — |
| 1978 | 55° | 33° | 44° | — | — |
| 1977 | 53° | 41° | 47° | — | — |
| 1976 | 61° | 37° | 49° | — | — |
| 1975 | 58° | 37° | 47° | — | — |
| 1974 | 55° | 41° | 48° | — | — |
| 1973 | 64° | 42° | 53° | — | — |
| 1972 | 59° | 57° | 58° | — | — |
| 1971 | 49° | 41° | 45° | 0.03" | — |
55 years of data from MOFFETT FED AIRFIELD