All-time weather records — Portsmouth, IA

Record high
114.1°F
July 25, 1936
Record low
-36.9°F
January 12, 1912
Wettest day
7.83 in
September 11, 1972

Climate change signal in Portsmouth

0.5%

of Portsmouth's all-time daily heat records were set in the last decade (2 of 366 records since 2015).

0%

of all-time daily cold records were set in the last decade (0 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 #
1890s
3
9
1900s
19
67
1910s
26
64
1920s
23
40
1930s
112
38
1940s
25
25
1950s
32
24
1960s
13
33
1970s
13
20
1980s
32
17
1990s
21
13
2000s
28
7
2010s
19
9

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 1899, the latest in 2015. Period of observation: 1899-2016.

Records by month

Month Hottest day Coldest day Wettest day
January 68.0°F — Jan 25, 1944 -36.9°F — Jan 12, 1912 1.35 in — Jan 28, 1909
February 71.1°F — Feb 11, 1999 -36.9°F — Feb 2, 1905 1.59 in — Feb 19, 1954
March 90.0°F — Mar 25, 1907 -23.1°F — Mar 5, 1960 2.91 in — Mar 28, 2004
April 93.9°F — Apr 28, 1910 1.9°F — Apr 3, 1975 3.00 in — Apr 19, 1920
May 106.0°F — May 30, 1934 18.0°F — May 2, 1908 5.37 in — May 21, 1962
June 107.1°F — Jun 6, 1933 30.9°F — Jun 3, 1969 4.10 in — Jun 30, 2014
July 114.1°F — Jul 25, 1936 39.9°F — Jul 5, 1972 6.72 in — Jul 2, 1958
August 111.0°F — Aug 5, 1934 35.1°F — Aug 31, 1967 5.15 in — Aug 29, 1952
September 106.0°F — Sep 3, 2000 19.9°F — Sep 29, 1899 7.83 in — Sep 11, 1972
October 93.9°F — Oct 2, 1953 0.0°F — Oct 28, 1925 3.70 in — Oct 11, 1986
November 80.1°F — Nov 3, 2005 -16.1°F — Nov 21, 1937 4.08 in — Nov 13, 1909
December 68.0°F — Dec 6, 1939 -27.0°F — Dec 10, 1919 2.17 in — Dec 14, 2015

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