Weather on September 18
Irvine, CA
55 Years of Data
About This Date
September 18th in Irvine, CA typically brings warm fall weather, with average highs around 84°F and lows near 59°F — a 25°F daily swing. Over 56 years of records, the warmest September 18th was in 1984 (83°F average), while the coldest was 1985 (62°F) — a 21°F range across recorded history. Rain or other precipitation has occurred on about 2% of September 18th 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 18th in Irvine, CA? Stay hydrated and seek shade during peak afternoon hours.
| Year | High | Low | Avg | Precip | Snow |
|---|---|---|---|---|---|
| 2026 | 80° | 59° | 70° | — | — |
| 2025 | 86° | 67° | 76° | 0.1" | — |
| 2024 | 75° | 55° | 65° | — | — |
| 2023 | 75° | 60° | 68° | — | — |
| 2022 | 79° | 63° | 71° | — | — |
| 2021 | 80° | 61° | 70° | — | — |
| 2020 | 95° | 64° | 80° | — | — |
| 2019 | 83° | 59° | 71° | — | — |
| 2018 | 88° | 66° | 77° | — | — |
| 2017 | 82° | 61° | 71° | — | — |
| 2016 | 85° | 62° | 73° | — | — |
| 2015 | 90° | 62° | 76° | — | — |
| 2014 | 93° | 64° | 79° | — | — |
| 2013 | 82° | 57° | 70° | — | — |
| 2012 | 88° | 54° | 71° | — | — |
| 2011 | 84° | 56° | 70° | — | — |
| 2010 | 84° | 48° | 66° | — | — |
| 2009 | 94° | 59° | 76° | — | — |
| 2008 | 91° | 61° | 76° | — | — |
| 2007 | 82° | 56° | 69° | — | — |
| 2006 | 95° | 50° | 73° | — | — |
| 2005 | 81° | 60° | 70° | — | — |
| 2004 | 87° | 60° | 74° | — | — |
| 2003 | 88° | 59° | 73° | — | — |
| 2002 | 80° | 62° | 71° | — | — |
| 2001 | 86° | 61° | 73° | — | — |
| 2000 | 91° | 62° | 77° | — | — |
| 1999 | 70° | 62° | 66° | — | — |
| 1998 | 85° | 57° | 71° | — | — |
| 1997 | 97° | 62° | 79° | — | — |
| 1996 | 84° | 64° | 74° | — | — |
| 1995 | 85° | 59° | 72° | — | — |
| 1994 | 88° | 64° | 76° | — | — |
| 1993 | 79° | 48° | 63° | — | — |
| 1992 | 88° | 60° | 74° | — | — |
| 1991 | 86° | 60° | 73° | — | — |
| 1990 | 80° | 62° | 71° | — | — |
| 1989 | 68° | 59° | 64° | — | — |
| 1988 | 76° | 60° | 68° | — | — |
| 1987 | 84° | 55° | 70° | — | — |
| 1986 | 82° | 53° | 68° | — | — |
| 1985coldest | 69° | 55° | 62° | — | — |
| 1984warmest | 97° | 69° | 83° | — | — |
| 1983 | 92° | 69° | 80° | — | — |
| 1982 | 82° | — | — | — | — |
| 1981 | 94° | 59° | 76° | — | — |
| 1980 | 83° | 56° | 69° | — | — |
| 1979 | 97° | 61° | 79° | — | — |
| 1978 | 75° | 50° | 63° | — | — |
| 1977 | 79° | 52° | 65° | — | — |
| 1976 | 75° | 55° | 65° | — | — |
| 1975 | 94° | 63° | 78° | — | — |
| 1974 | 79° | 60° | 69° | — | — |
| 1973 | 77° | 52° | 64° | — | — |
| 1972 | 75° | 52° | 63° | — | — |
| 1971 | 86° | 65° | 75° | — | — |
Irvine, CA Temperature Range by Month
Average monthly highs and lows. The shaded band shows the typical daily temperature range.
Irvine, CA Monthly Precipitation
Average rainfall per month, in inches.
Irvine, 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 Irvine, CA
Most pleasant months in Irvine, CA: January, February, March, April, May, June, October, November, December.
What to expect on September 18th
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 18th outlook →