All-time weather records — Issaquah, WA

Record high
109.0°F
June 28, 2021
Record low
-57.8°F
November 10, 2010
Wettest day
4.48 in
October 20, 2003

Climate change signal in Issaquah

53.8%

of Issaquah's all-time daily heat records were set in the last decade (197 of 366 records since 2015).

25.7%

of all-time daily cold records were set in the last decade (94 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
16
22
2000s
115
167
2010s
133
120
2020s
102
57

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 64.0°F — Jan 15, 2018 17.2°F — Jan 12, 2024 2.12 in — Jan 17, 2005
February 66.0°F — Feb 17, 2016 18.1°F — Feb 10, 2019 1.40 in — Feb 28, 2022
March 79.0°F — Mar 19, 2019 -16.1°F — Mar 13, 2000 1.70 in — Mar 15, 2015
April 87.1°F — Apr 18, 2016 31.1°F — Apr 2, 2008 1.36 in — Apr 13, 2002
May 91.9°F — May 14, 2023 37.0°F — May 1, 2011 1.11 in — May 3, 2014
June 109.0°F — Jun 28, 2021 44.1°F — Jun 8, 2002 1.21 in — Jun 11, 2001
July 105.1°F — Jul 29, 2009 48.9°F — Jul 5, 2000 1.05 in — Jul 23, 2014
August 98.1°F — Aug 16, 2020 46.9°F — Aug 24, 2003 1.02 in — Aug 24, 2008
September 91.0°F — Sep 10, 2020 39.9°F — Sep 23, 2000 1.66 in — Sep 28, 2013
October 86.0°F — Oct 16, 2022 28.0°F — Oct 31, 2003 4.48 in — Oct 20, 2003
November 75.0°F — Nov 3, 2010 -57.8°F — Nov 10, 2010 3.16 in — Nov 25, 1998
December 68.0°F — Dec 10, 2014 15.1°F — Dec 20, 1998 2.64 in — Dec 20, 2019

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