Weather on September 20
Mission Viejo, CA
55 Years of Data
About This Date
September 20th in Mission Viejo, CA typically brings warm fall weather, with average highs around 81°F and lows near 60°F. Over 56 years of records, the warmest September 20th was in 2015 (87°F average), while the coldest was 2007 (61°F) — a 26°F range across recorded history. Rain or other precipitation has occurred on about 4% of September 20th dates historically. 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 September 20th in Mission Viejo, CA? Stay hydrated and seek shade during peak afternoon hours.
| Year | High | Low | Avg | Precip | Snow |
|---|---|---|---|---|---|
| 2026 | 81° | 62° | 71° | — | — |
| 2025 | 86° | 63° | 74° | — | — |
| 2024 | 75° | 59° | 67° | — | — |
| 2023 | 75° | 61° | 68° | — | — |
| 2022 | 84° | 58° | 71° | — | — |
| 2021 | 82° | 57° | 70° | — | — |
| 2020 | 83° | 57° | 70° | — | — |
| 2019 | 78° | 57° | 68° | — | — |
| 2018 | 78° | 58° | 68° | — | — |
| 2017 | 72° | 62° | 67° | — | — |
| 2016 | 81° | 69° | 75° | — | — |
| 2015warmest | 104° | 69° | 87° | — | — |
| 2014 | 78° | 62° | 70° | — | — |
| 2013 | 70° | 61° | 65° | — | — |
| 2012 | 93° | 62° | 78° | — | — |
| 2011 | 79° | 56° | 67° | — | — |
| 2010 | 79° | 55° | 67° | — | — |
| 2009 | 87° | 60° | 74° | — | — |
| 2008 | 77° | 57° | 67° | — | — |
| 2007coldest | 71° | 52° | 61° | — | — |
| 2006 | 81° | 56° | 68° | — | — |
| 2005 | 88° | 61° | 74° | — | — |
| 2004 | 77° | 53° | 65° | — | — |
| 2003 | 87° | 56° | 71° | — | — |
| 2002 | 94° | 58° | 76° | — | — |
| 2001 | 80° | 57° | 69° | — | — |
| 2000 | 79° | 64° | 71° | — | — |
| 1999 | 86° | 52° | 69° | — | — |
| 1998 | 76° | 62° | 69° | — | — |
| 1997 | 77° | 59° | 68° | — | — |
| 1996 | 82° | 63° | 72° | — | — |
| 1995 | 80° | 61° | 70° | — | — |
| 1994 | 79° | 60° | 69° | — | — |
| 1993 | 69° | 62° | 66° | — | — |
| 1992 | 89° | 58° | 73° | — | — |
| 1991 | 87° | 66° | 77° | — | — |
| 1990 | 75° | 65° | 70° | — | — |
| 1989 | 79° | 55° | 67° | — | — |
| 1988 | 66° | 57° | 62° | 0.18" | — |
| 1987 | 77° | 58° | 67° | — | — |
| 1986 | 73° | 56° | 64° | — | — |
| 1985 | 80° | 57° | 69° | — | — |
| 1984 | 86° | 68° | 77° | — | — |
| 1983 | 77° | 71° | 74° | 0.27" | — |
| 1982 | 82° | 57° | 70° | — | — |
| 1981 | 89° | 62° | 76° | — | — |
| 1980 | 77° | 60° | 69° | — | — |
| 1979 | 90° | 66° | 78° | — | — |
| 1978 | 88° | 66° | 77° | — | — |
| 1977 | 76° | 58° | 67° | — | — |
| 1976 | 75° | 66° | 71° | — | — |
| 1975 | 85° | 63° | 74° | — | — |
| 1974 | 78° | 57° | 68° | — | — |
| 1973 | 76° | 55° | 65° | — | — |
| 1972 | 85° | 54° | 69° | — | — |
| 1971 | 78° | 58° | 68° | — | — |
Mission Viejo, CA Temperature Range by Month
Average monthly highs and lows. The shaded band shows the typical daily temperature range.
Mission Viejo, CA Monthly Precipitation
Average rainfall per month, in inches.
Mission Viejo, 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 Mission Viejo, CA
Most pleasant months in Mission Viejo, CA: January, February, March, April, May, June, October, November, December.
What to expect on September 20th
This page shows what actually happened each year. For the odds — typical high and low, and how often it stays dry — see the climatological outlook for this date.
September 20th outlook →