Weather on May 20
San Marcos, CA
55 Years of Data
Avg High
75°F
Avg Low
55°F
Warmest
2017
75°F avg
Coldest
1975
54°F avg
About This Date
May 20th in San Marcos, CA typically brings pleasant spring weather, with average highs around 75°F and lows near 55°F. Over 55 years of records, the warmest May 20th was in 2017 (75°F average), while the coldest was 1975 (54°F) — a 21°F range across recorded history. Rain or other precipitation has occurred on about 13% of May 20th dates historically, with the wettest May 20th recording 1.45" of rain. The last decade has been 1.1°F warmer on this date compared to 20-30 years ago.
The last decade has been 1.1°F warmer on this date compared to 20-30 years ago.
Planning for May 20th in San Marcos, CA? Great weather for outdoor activities.
Warming Trend
0.7°F per decade on this date
| Year | High | Low | Avg | Precip | Snow |
|---|---|---|---|---|---|
| 2025 | 92° | 57° | 74° | — | — |
| 2024 | 77° | 56° | 66° | — | — |
| 2023 | 77° | 60° | 69° | — | — |
| 2022 | 67° | 58° | 62° | — | — |
| 2021 | 72° | 56° | 64° | — | — |
| 2020 | 72° | 56° | 64° | — | — |
| 2019 | 67° | 55° | 61° | 0.97" | — |
| 2018 | 70° | 58° | 64° | — | — |
| 2017warmest | 94° | 57° | 75° | — | — |
| 2016 | 72° | 59° | 65° | — | — |
| 2015 | 73° | 56° | 64° | — | — |
| 2014 | 72° | 58° | 65° | — | — |
| 2013 | 86° | 58° | 72° | — | — |
| 2012 | 82° | 57° | 70° | — | — |
| 2011 | 72° | 55° | 63° | — | — |
| 2010 | 66° | 53° | 60° | — | — |
| 2009 | 71° | 61° | 66° | — | — |
| 2008 | 68° | 60° | 64° | — | — |
| 2007 | 75° | 57° | 66° | — | — |
| 2006 | 68° | 61° | 64° | — | — |
| 2005 | 87° | 55° | 71° | — | — |
| 2004 | 66° | 59° | 63° | — | — |
| 2003 | 86° | 31° | 58° | — | — |
| 2002 | 69° | 55° | 62° | — | — |
| 2001 | 67° | 60° | 63° | — | — |
| 2000 | 88° | 53° | 70° | — | — |
| 1999 | 73° | 56° | 64° | — | — |
| 1998 | 74° | 55° | 64° | — | — |
| 1997 | 78° | 59° | 69° | — | — |
| 1996 | 79° | 60° | 69° | — | — |
| 1995 | 70° | 56° | 63° | — | — |
| 1994 | 74° | 46° | 60° | — | — |
| 1993 | 77° | 61° | 69° | — | — |
| 1992 | 81° | 57° | 69° | — | — |
| 1991 | 69° | 52° | 60° | — | — |
| 1990 | 71° | 56° | 63° | — | — |
| 1989 | 78° | 53° | 66° | — | — |
| 1988 | 89° | 57° | 73° | — | — |
| 1987 | 67° | 54° | 60° | 0.3" | — |
| 1986 | 82° | 56° | 69° | — | — |
| 1985 | 75° | 57° | 66° | — | — |
| 1984 | 78° | 58° | 68° | — | — |
| 1983 | 84° | 54° | 69° | — | — |
| 1982 | 75° | 58° | 66° | — | — |
| 1981 | 69° | 53° | 61° | 0.1" | — |
| 1980 | 78° | 56° | 67° | 0.05" | — |
| 1979 | 68° | 55° | 62° | 0.05" | — |
| 1978 | 80° | 55° | 68° | — | — |
| 1977 | 80° | 48° | 64° | — | — |
| 1976 | 75° | 56° | 65° | — | — |
| 1975coldest | 58° | 50° | 54° | 0.33" | — |
| 1974 | 74° | 41° | 57° | — | — |
| 1973 | 75° | 56° | 65° | — | — |
| 1972 | 66° | 49° | 57° | 1.45" | — |
| 1971 | 79° | 45° | 62° | — | — |
55 years of data from ESCONDIDO #2