All-time weather records — Costa Mesa, CA

Record high
109.9°F
September 27, 2010
Record low
12.2°F
March 15, 2008
Wettest day
3.24 in
December 6, 2018

Climate change signal in Costa Mesa

45.4%

of Costa Mesa's all-time daily heat records were set in the last decade (166 of 366 records since 2015).

10.7%

of all-time daily cold records were set in the last decade (39 of 366 records since 2015).

If records were spread evenly across the station's history, you'd expect roughly 5% per decade. Decade-by-decade, here's where each record-breaking day was set:

Decade Heat records set # Cold records set #
1990s
8
79
2000s
120
176
2010s
157
97
2020s
81
14

Records are the all-time daily extremes that are still standing — each daily record can only be held by one year. The station's earliest hot record was set in 1999, the latest in 2026. Period of observation: 1999-2026.

Records by month

Month Hottest day Coldest day Wettest day
January 90.0°F — Jan 15, 2021 33.1°F — Jan 14, 2007 2.27 in — Jan 22, 2017
February 91.0°F — Feb 9, 2022 36.0°F — Feb 2, 2016 2.11 in — Feb 12, 2001
March 95.0°F — Mar 11, 2007 12.2°F — Mar 15, 2008 2.19 in — Mar 15, 2003
April 102.9°F — Apr 7, 2022 41.0°F — Apr 10, 1999 0.82 in — Apr 12, 2010
May 106.0°F — May 14, 2014 48.9°F — May 1, 1999 0.57 in — May 22, 2006
June 96.1°F — Jun 9, 2020 54.0°F — Jun 2, 2011 0.10 in — Jun 2, 1999
July 108.0°F — Jul 6, 2018 57.0°F — Jul 28, 2007 0.31 in — Jul 15, 1999
August 100.0°F — Aug 18, 2020 57.9°F — Aug 27, 2003 2.01 in — Aug 20, 2023
September 109.9°F — Sep 27, 2010 55.9°F — Sep 21, 2007 1.49 in — Sep 15, 2015
October 106.0°F — Oct 24, 2017 46.0°F — Oct 29, 2009 2.68 in — Oct 20, 2004
November 100.0°F — Nov 3, 2010 37.0°F — Nov 30, 2004 1.61 in — Nov 15, 2025
December 90.0°F — Dec 12, 2010 36.0°F — Dec 27, 2003 3.24 in — Dec 6, 2018

Click a month to see every daily record for that month in Costa Mesa.