Weather on August 20
San Mateo, CA
55 Years of Data
Avg High
73°F
Avg Low
56°F
Warmest
2023
75°F avg
Coldest
2001
58°F avg
About This Date
August 20th in San Mateo, CA typically brings pleasant summer weather, with average highs around 73°F and lows near 56°F. Over 55 years of records, the warmest August 20th was in 2023 (75°F average), while the coldest was 2001 (58°F) — a 17°F range across recorded history. Rain or other precipitation has occurred on about 4% of August 20th dates historically. The last decade has been 3.5°F warmer on this date compared to 20-30 years ago.
The last decade has been 3.5°F warmer on this date compared to 20-30 years ago.
Planning for August 20th in San Mateo, CA? Great weather for outdoor activities.
Warming Trend
0.4°F per decade on this date
| Year | High | Low | Avg | Precip | Snow |
|---|---|---|---|---|---|
| 2025 | 82° | 57° | 70° | — | — |
| 2024 | 76° | 53° | 64° | — | — |
| 2023warmest | 89° | 61° | 75° | — | — |
| 2022 | 77° | 58° | 67° | — | — |
| 2021 | 73° | 60° | 67° | — | — |
| 2020 | 77° | 55° | 66° | — | — |
| 2019 | 72° | 61° | 66° | — | — |
| 2018 | 72° | 55° | 63° | — | — |
| 2017 | 72° | 61° | 66° | — | — |
| 2016 | 69° | 58° | 63° | — | — |
| 2015 | 69° | 61° | 65° | — | — |
| 2014 | 73° | 62° | 68° | — | — |
| 2013 | 76° | 59° | 67° | — | — |
| 2012 | 64° | 52° | 58° | — | — |
| 2011 | 68° | 56° | 62° | — | — |
| 2010 | 70° | 55° | 62° | — | — |
| 2009 | 72° | 56° | 64° | — | — |
| 2008 | 76° | 59° | 67° | — | — |
| 2007 | 74° | 60° | 67° | — | — |
| 2006 | 68° | 55° | 62° | — | — |
| 2005 | 65° | 55° | 60° | — | — |
| 2004 | 76° | 60° | 68° | — | — |
| 2003 | 77° | 60° | 69° | — | — |
| 2002 | 72° | 52° | 62° | — | — |
| 2001coldest | 60° | 56° | 58° | — | — |
| 2000 | 73° | 53° | 63° | — | — |
| 1999 | 69° | 56° | 62° | — | — |
| 1998 | 66° | 57° | 62° | — | — |
| 1997 | 73° | 59° | 66° | 0.1" | — |
| 1996 | 71° | 54° | 62° | — | — |
| 1995 | 74° | 57° | 65° | — | — |
| 1994 | 72° | 54° | 63° | — | — |
| 1993 | 70° | 57° | 63° | — | — |
| 1992 | 66° | 53° | 60° | — | — |
| 1991 | 67° | 57° | 62° | — | — |
| 1990 | 74° | 58° | 66° | — | — |
| 1989 | 73° | 56° | 64° | — | — |
| 1988 | 76° | 56° | 66° | — | — |
| 1987 | 71° | 57° | 64° | — | — |
| 1986 | 67° | 53° | 60° | — | — |
| 1985 | 70° | 56° | 63° | — | — |
| 1984 | 75° | 52° | 63° | — | — |
| 1983 | 76° | 56° | 66° | — | — |
| 1982 | 70° | 54° | 62° | — | — |
| 1981 | 70° | 55° | 62° | — | — |
| 1980 | 71° | 54° | 62° | — | — |
| 1979 | 75° | 59° | 67° | — | — |
| 1978 | 77° | 55° | 66° | — | — |
| 1977 | 71° | 56° | 63° | — | — |
| 1976 | 83° | 56° | 69° | 0.05" | — |
| 1975 | 73° | — | — | — | — |
| 1974 | 80° | 51° | 66° | — | — |
| 1973 | 71° | 49° | 60° | — | — |
| 1972 | 76° | 59° | 67° | — | — |
| 1971 | 81° | 57° | 69° | — | — |
55 years of data from BURLINGAME