All-time weather records — Rancho Cucamonga, CA

Record high
118.0°F
September 5, 2020
Record low
25.2°F
January 14, 2007
Wettest day
3.62 in
February 5, 2024

Climate change signal in Rancho Cucamonga

46.4%

of Rancho Cucamonga's all-time daily heat records were set in the last decade (170 of 366 records since 2015).

17.2%

of all-time daily cold records were set in the last decade (63 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
22
73
2000s
110
149
2010s
150
114
2020s
84
30

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 90.0°F — Jan 31, 2003 25.2°F — Jan 14, 2007 3.23 in — Jan 9, 2005
February 91.0°F — Feb 27, 2026 29.1°F — Feb 20, 2018 3.62 in — Feb 5, 2024
March 100.0°F — Mar 19, 2026 33.1°F — Mar 2, 2023 2.53 in — Mar 15, 2003
April 100.9°F — Apr 26, 2004 33.1°F — Apr 10, 1999 1.66 in — Apr 6, 2020
May 102.9°F — May 3, 2004 42.1°F — May 1, 1999 1.26 in — May 6, 2016
June 111.9°F — Jun 20, 2016 46.0°F — Jun 5, 1999 0.24 in — Jun 2, 1999
July 117.0°F — Jul 6, 2018 55.9°F — Jul 1, 2004 0.44 in — Jul 26, 2021
August 111.9°F — Aug 31, 2017 55.9°F — Aug 8, 1999 1.69 in — Aug 20, 2023
September 118.0°F — Sep 5, 2020 51.1°F — Sep 27, 2013 1.25 in — Sep 15, 2015
October 107.1°F — Oct 1, 2012 41.0°F — Oct 31, 2019 1.37 in — Oct 27, 2004
November 98.1°F — Nov 3, 2010 32.0°F — Nov 19, 2015 1.82 in — Nov 28, 2019
December 87.1°F — Dec 1, 2021 28.0°F — Dec 22, 1998 2.84 in — Dec 21, 2010

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