All-time weather records — Hayward, CA

Record high
108.0°F
September 2, 2017
Record low
0.0°F
December 7, 2007
Wettest day
4.34 in
December 31, 2022

Climate change signal in Hayward

48.6%

of Hayward's all-time daily heat records were set in the last decade (178 of 366 records since 2015).

18.3%

of all-time daily cold records were set in the last decade (67 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
14
49
2000s
118
160
2010s
129
120
2020s
105
37

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 1998, the latest in 2026. Period of observation: 1998-2026.

Records by month

Month Hottest day Coldest day Wettest day
January 79.0°F — Jan 18, 2021 28.0°F — Jan 15, 2007 1.96 in — Jan 24, 2000
February 81.0°F — Feb 3, 2018 33.1°F — Feb 23, 2018 2.12 in — Feb 13, 2000
March 88.0°F — Mar 20, 2026 36.0°F — Mar 8, 2002 1.31 in — Mar 24, 2011
April 95.0°F — Apr 20, 2009 36.0°F — Apr 9, 1999 1.01 in — Apr 6, 2018
May 99.0°F — May 15, 2008 41.0°F — May 11, 2022 0.90 in — May 4, 2024
June 104.0°F — Jun 14, 2000 46.9°F — Jun 5, 2014 0.89 in — Jun 28, 2011
July 105.1°F — Jul 22, 2006 53.1°F — Jul 4, 1999 0.01 in — Jul 9, 2015
August 102.9°F — Aug 14, 2020 53.1°F — Aug 11, 2012 0.11 in — Aug 6, 1999
September 108.0°F — Sep 2, 2017 46.9°F — Sep 26, 2013 0.45 in — Sep 13, 2009
October 102.0°F — Oct 6, 2024 43.0°F — Oct 31, 2002 3.32 in — Oct 24, 2021
November 84.9°F — Nov 14, 2008 33.1°F — Nov 25, 2010 1.68 in — Nov 8, 2022
December 75.9°F — Dec 7, 2020 0.0°F — Dec 7, 2007 4.34 in — Dec 31, 2022

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