Weather on May 18
San Marcos, CA
55 Years of Data
About This Date
May 18th in San Marcos, CA typically brings pleasant spring weather, with average highs around 76°F and lows near 55°F. Over 56 years of records, the warmest May 18th was in 2008 (74°F average), while the coldest was 2000 (55°F) — a 19°F range across recorded history. Rain or other precipitation has occurred on about 5% of May 18th dates historically, with the wettest May 18th recording 0.86" of rain. Temperatures on this date have remained relatively stable over the past several decades.
Temperatures on this date have remained relatively stable over the past several decades.
Planning for May 18th in San Marcos, CA? Great weather for outdoor activities.
| Year | High | Low | Avg | Precip | Snow |
|---|---|---|---|---|---|
| 2026 | 68° | 60° | 64° | — | — |
| 2025 | 68° | 56° | 62° | 0.08" | — |
| 2024 | 80° | 59° | 70° | — | — |
| 2023 | 74° | 57° | 65° | — | — |
| 2022 | 78° | 57° | 68° | — | — |
| 2021 | 74° | 57° | 65° | — | — |
| 2020 | 76° | 61° | 68° | — | — |
| 2019 | 77° | 51° | 64° | — | — |
| 2018 | 73° | 57° | 65° | — | — |
| 2017 | 78° | 55° | 67° | — | — |
| 2016 | 78° | 61° | 69° | — | — |
| 2015 | 71° | 57° | 64° | — | — |
| 2014 | 81° | 61° | 71° | — | — |
| 2013 | 73° | 59° | 66° | — | — |
| 2012 | 72° | 57° | 64° | — | — |
| 2011 | 63° | 54° | 58° | 0.86" | — |
| 2010 | 65° | 55° | 60° | — | — |
| 2009 | 69° | 60° | 65° | — | — |
| 2008warmest | 84° | 65° | 74° | — | — |
| 2007 | 64° | 58° | 61° | — | — |
| 2006 | 66° | 61° | 63° | — | — |
| 2005 | 79° | 56° | 67° | — | — |
| 2004 | 69° | 60° | 65° | — | — |
| 2003 | 80° | 33° | 57° | — | — |
| 2002 | 76° | 56° | 66° | — | — |
| 2001 | 78° | 59° | 69° | — | — |
| 2000coldest | 77° | 33° | 55° | — | — |
| 1999 | 80° | 53° | 67° | — | — |
| 1998 | 81° | 49° | 65° | — | — |
| 1997 | 79° | 63° | 71° | — | — |
| 1996 | 81° | 58° | 69° | — | — |
| 1995 | 74° | 57° | 65° | — | — |
| 1994 | 64° | 59° | 62° | 0.03" | — |
| 1993 | 78° | 58° | 68° | — | — |
| 1992 | 80° | 60° | 70° | — | — |
| 1991 | 68° | 51° | 60° | — | — |
| 1990 | 72° | 54° | 63° | — | — |
| 1989 | 73° | 57° | 65° | — | — |
| 1988 | 74° | 57° | 65° | — | — |
| 1987 | 72° | 59° | 65° | — | — |
| 1986 | 89° | 55° | 72° | — | — |
| 1985 | 77° | 50° | 64° | — | — |
| 1984 | 80° | 50° | 65° | — | — |
| 1983 | 90° | 52° | 71° | — | — |
| 1982 | 86° | 58° | 72° | — | — |
| 1981 | 82° | 50° | 66° | — | — |
| 1980 | 80° | 55° | 68° | — | — |
| 1979 | 73° | 52° | 62° | — | — |
| 1978 | 95° | 50° | 73° | — | — |
| 1977 | 72° | 44° | 58° | — | — |
| 1976 | 80° | 55° | 68° | — | — |
| 1975 | 70° | 58° | 64° | — | — |
| 1974 | 68° | 47° | 57° | — | — |
| 1973 | 79° | 56° | 67° | — | — |
| 1972 | 68° | 55° | 62° | — | — |
| 1971 | 87° | 46° | 67° | — | — |
San Marcos, CA Temperature Range by Month
Average monthly highs and lows. The shaded band shows the typical daily temperature range.
San Marcos, CA Monthly Precipitation
Average rainfall per month, in inches.
San Marcos, CA Daily Temperature Calendar
Average daily high temperature for every day of the year. Each cell is the climatological mean for that calendar day across 55 years of NOAA data.
Best Time to Visit San Marcos, CA
Most pleasant months in San Marcos, CA: June.