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Topics / Climate / United States / Iowa

Was September normal in Iowa?

September 2026 · 99 counties · data family: climatedata.dev

Much warmer than normal

68.3°FStatewide average temperature, September 2026

+4.6°F against the 1991–2020 normal of 63.7°F
5th warmest September of 132 since 1895
Of 99 counties: 86 much warmer, 13 warmer
Furthest above normal: Fremont County (+6.6°F); least: Allamakee County (+2.5°F)
Precipitation 7.83 in, 225% of normal: much wetter than normal

Every Iowa county, September 2026September 2026 was warmer than normal in every county with a figure: 86 much warmer, 13 warmer; furthest above normal Fremont County (+6.6°F), least Allamakee County (+2.5°F).Choose a county to see its answer. The colour shows how far each county was from its own 1991–2020 normal.

+4°F or more 74
+3 to +4°F 23
+2 to +3°F 2
+1 to +2°F 0
within 1°F 0
−1 to −2°F 0

Much warmer than normal 86
Warmer than normal 13
Near normal 0
Cooler than normal 0
Much cooler than normal 0

Every September since 1895, Iowa statewideSeptember 2026 averaged 68.3°F, +4.6°F against the 1991–2020 normal: the 5th warmest September of 132 since 1895.

Show the numbers (132 rows)

Year	September average
2026	68.3°F
2025	66.9°F
2024	66.7°F
2023	67.2°F
2022	65.1°F
2021	66.6°F
2020	61.9°F
2019	68.2°F
2018	65.9°F
2017	66.7°F
2016	67.3°F
2015	68.4°F
2014	62.0°F
2013	67.0°F
2012	62.1°F
2011	60.2°F
2010	63.1°F
2009	63.3°F
2008	63.5°F
2007	64.7°F
2006	60.0°F
2005	67.6°F
2004	66.4°F
2003	61.1°F
2002	65.3°F
2001	61.2°F
2000	64.6°F
1999	61.3°F
1998	68.2°F
1997	64.2°F
1996	60.7°F
1995	60.2°F
1994	64.3°F
1993	57.4°F
1992	60.8°F
1991	62.4°F
1990	66.2°F
1989	60.5°F
1988	64.7°F
1987	62.8°F
1986	64.7°F
1985	62.7°F
1984	61.1°F
1983	64.2°F
1982	61.8°F
1981	62.7°F
1980	64.3°F
1979	64.2°F
1978	67.5°F
1977	63.7°F
1976	62.4°F
1975	58.7°F
1974	58.3°F
1973	62.2°F
1972	62.9°F
1971	64.9°F
1970	62.9°F
1969	62.9°F
1968	61.8°F
1967	60.1°F
1966	60.5°F
1965	58.8°F
1964	62.1°F
1963	64.1°F
1962	59.8°F
1961	61.0°F
1960	64.4°F
1959	62.7°F
1958	63.6°F
1957	59.9°F
1956	62.2°F
1955	65.4°F
1954	65.1°F
1953	63.7°F
1952	63.8°F
1951	58.7°F
1950	62.0°F
1949	58.2°F
1948	66.8°F
1947	66.4°F
1946	62.1°F
1945	61.8°F
1944	63.2°F
1943	59.0°F
1942	60.2°F
1941	65.4°F
1940	64.9°F
1939	68.2°F
1938	65.8°F
1937	64.9°F
1936	67.0°F
1935	64.0°F
1934	59.9°F
1933	68.4°F
1932	61.1°F
1931	70.0°F
1930	65.2°F
1929	61.4°F
1928	59.5°F
1927	66.3°F
1926	62.0°F
1925	67.9°F
1924	57.8°F
1923	63.2°F
1922	66.0°F
1921	66.2°F
1920	65.4°F
1919	66.4°F
1918	57.5°F
1917	61.8°F
1916	61.7°F
1915	62.8°F
1914	63.6°F
1913	63.5°F
1912	61.3°F
1911	64.8°F
1910	62.4°F
1909	61.5°F
1908	67.0°F
1907	61.9°F
1906	66.3°F
1905	65.0°F
1904	63.1°F
1903	60.1°F
1902	58.2°F
1901	62.4°F
1900	63.8°F
1899	61.7°F
1898	64.5°F
1897	70.0°F
1896	57.4°F
1895	66.8°F

All 99 counties, September 2026

Record rank: 1 is the warmest September on record for that county.


1	Fremont	72.8°F	+6.6°F	3 of 132	Much warmer than normal
2	Page	72.2°F	+6.6°F	3 of 132	Much warmer than normal
3	Decatur	71.6°F	+6.5°F	3 of 132	Much warmer than normal
4	Mills	72.2°F	+6.4°F	4 of 132	Much warmer than normal
5	Taylor	71.4°F	+6.4°F	3 of 132	Much warmer than normal
6	Wayne	71.2°F	+6.4°F	3 of 132	Much warmer than normal
7	Ringgold	71.3°F	+6.3°F	3 of 132	Much warmer than normal
8	Appanoose	71.4°F	+6.2°F	3 of 132	Much warmer than normal
9	Louisa	71.6°F	+6.2°F	2 of 132	Much warmer than normal
10	Monroe	71.1°F	+5.9°F	3 of 132	Much warmer than normal
11	Montgomery	71.0°F	+5.9°F	3 of 132	Much warmer than normal
12	Muscatine	70.9°F	+5.9°F	1 of 132	Much warmer than normal
13	Monona	70.2°F	+5.8°F	1 of 132	Much warmer than normal
14	Des Moines	71.6°F	+5.7°F	3 of 132	Much warmer than normal
15	Harrison	70.6°F	+5.7°F	4 of 132	Much warmer than normal
16	Lucas	70.6°F	+5.7°F	3 of 132	Much warmer than normal
17	Adams	70.2°F	+5.6°F	5 of 132	Much warmer than normal
18	Clarke	70.4°F	+5.6°F	5 of 132	Much warmer than normal
19	Davis	71.1°F	+5.6°F	3 of 132	Much warmer than normal
20	Mahaska	70.6°F	+5.6°F	3 of 132	Much warmer than normal
21	Union	70.1°F	+5.6°F	5 of 132	Much warmer than normal
22	Wapello	70.9°F	+5.6°F	3 of 132	Much warmer than normal
23	Crawford	69.0°F	+5.5°F	4 of 132	Much warmer than normal
24	Keokuk	70.2°F	+5.5°F	3 of 132	Much warmer than normal
25	Lee	72.0°F	+5.5°F	4 of 132	Much warmer than normal
26	Henry	70.8°F	+5.4°F	3 of 132	Much warmer than normal
27	Pottawattamie	70.5°F	+5.4°F	4 of 132	Much warmer than normal
28	Ida	68.5°F	+5.3°F	5 of 132	Much warmer than normal
29	Marion	70.5°F	+5.3°F	5 of 132	Much warmer than normal
30	Scott	70.3°F	+5.3°F	2 of 132	Much warmer than normal
31	Woodbury	69.2°F	+5.3°F	5 of 132	Much warmer than normal
32	Van Buren	70.8°F	+5.2°F	4 of 132	Much warmer than normal
33	Washington	70.1°F	+5.2°F	3 of 132	Much warmer than normal
34	Adair	69.1°F	+5.1°F	5 of 132	Much warmer than normal
35	Guthrie	68.9°F	+5.1°F	5 of 132	Much warmer than normal
36	Shelby	69.0°F	+5.1°F	5 of 132	Much warmer than normal
37	Audubon	68.3°F	+5.0°F	6 of 132	Much warmer than normal
38	Cass	69.2°F	+5.0°F	5 of 132	Much warmer than normal
39	Delaware	67.5°F	+5.0°F	4 of 132	Much warmer than normal
40	Carroll	68.3°F	+4.9°F	6 of 132	Much warmer than normal
41	Clinton	69.3°F	+4.9°F	3 of 132	Much warmer than normal
42	Jefferson	70.0°F	+4.9°F	5 of 132	Much warmer than normal
43	Jasper	69.4°F	+4.8°F	4 of 132	Much warmer than normal
44	Cedar	68.9°F	+4.7°F	4 of 132	Much warmer than normal
45	Johnson	69.1°F	+4.7°F	4 of 132	Much warmer than normal
46	Plymouth	68.0°F	+4.7°F	5 of 132	Much warmer than normal
47	Sac	67.9°F	+4.7°F	6 of 132	Much warmer than normal
48	Jackson	68.4°F	+4.6°F	5 of 132	Much warmer than normal
49	Madison	69.3°F	+4.6°F	7 of 132	Much warmer than normal
50	Poweshiek	68.6°F	+4.6°F	6 of 132	Much warmer than normal
51	Dallas	69.1°F	+4.5°F	8 of 132	Much warmer than normal
52	Greene	68.3°F	+4.5°F	7 of 132	Much warmer than normal
53	Iowa	68.6°F	+4.5°F	7 of 132	Much warmer than normal
54	Cherokee	67.2°F	+4.4°F	8 of 132	Much warmer than normal
55	Marshall	68.1°F	+4.4°F	8 of 132	Much warmer than normal
56	Buchanan	66.9°F	+4.3°F	5 of 132	Much warmer than normal
57	Linn	67.7°F	+4.3°F	7 of 132	Much warmer than normal
58	Lyon	66.4°F	+4.3°F	9 of 132	Much warmer than normal
59	Sioux	66.8°F	+4.3°F	10 of 132	Much warmer than normal
60	Warren	69.6°F	+4.3°F	11 of 132	Much warmer than normal
61	Dubuque	67.1°F	+4.2°F	7 of 132	Much warmer than normal
62	Jones	67.7°F	+4.2°F	8 of 132	Much warmer than normal
63	Mitchell	65.6°F	+4.2°F	6 of 132	Much warmer than normal
64	Story	68.1°F	+4.2°F	9 of 132	Much warmer than normal
65	Worth	65.8°F	+4.2°F	6 of 132	Much warmer than normal
66	Buena Vista	66.7°F	+4.1°F	14 of 132	Warmer than normal
67	Calhoun	67.4°F	+4.1°F	11 of 132	Much warmer than normal
68	Hardin	67.0°F	+4.1°F	8 of 132	Much warmer than normal
69	Winnebago	65.8°F	+4.1°F	9 of 132	Much warmer than normal
70	Boone	68.0°F	+4.0°F	9 of 132	Much warmer than normal
71	Emmet	66.0°F	+4.0°F	7 of 132	Much warmer than normal
72	Floyd	66.2°F	+4.0°F	8 of 132	Much warmer than normal
73	Grundy	66.9°F	+4.0°F	10 of 132	Much warmer than normal
74	Polk	69.0°F	+4.0°F	10 of 132	Much warmer than normal
75	Cerro Gordo	65.9°F	+3.9°F	10 of 132	Much warmer than normal
76	Clayton	66.2°F	+3.9°F	9 of 132	Much warmer than normal
77	Benton	67.1°F	+3.8°F	11 of 132	Much warmer than normal
78	Black Hawk	66.8°F	+3.8°F	9 of 132	Much warmer than normal
79	Chickasaw	65.2°F	+3.8°F	10 of 132	Much warmer than normal
80	Howard	64.5°F	+3.8°F	8 of 132	Much warmer than normal
81	O'Brien	66.0°F	+3.8°F	16 of 132	Warmer than normal
82	Palo Alto	66.3°F	+3.8°F	10 of 132	Much warmer than normal
83	Tama	67.2°F	+3.8°F	11 of 132	Much warmer than normal
84	Kossuth	66.1°F	+3.7°F	13 of 132	Much warmer than normal
85	Osceola	65.4°F	+3.7°F	15 of 132	Warmer than normal
86	Bremer	66.0°F	+3.6°F	11 of 132	Much warmer than normal
87	Pocahontas	66.4°F	+3.6°F	13 of 132	Much warmer than normal
88	Butler	66.3°F	+3.5°F	12 of 132	Much warmer than normal
89	Clay	65.9°F	+3.5°F	14 of 132	Warmer than normal
90	Hamilton	66.6°F	+3.5°F	10 of 132	Much warmer than normal
91	Hancock	65.6°F	+3.5°F	14 of 132	Warmer than normal
92	Dickinson	65.3°F	+3.3°F	15 of 132	Warmer than normal
93	Fayette	65.1°F	+3.3°F	15 of 132	Warmer than normal
94	Webster	66.4°F	+3.3°F	14 of 132	Warmer than normal
95	Franklin	65.6°F	+3.2°F	17 of 132	Warmer than normal
96	Winneshiek	64.4°F	+3.1°F	15 of 132	Warmer than normal
97	Wright	65.5°F	+3.0°F	20 of 132	Warmer than normal
98	Humboldt	65.7°F	+2.8°F	22 of 132	Warmer than normal
99	Allamakee	64.5°F	+2.5°F	23 of 132	Warmer than normal

Get this data

This page's numbers, as JSON:

curl https://visualizedata.org/data/topics/climate/us-ia.json

The climatedata.dev API it comes from (live, no key; every month since 1895 with its normal, anomaly and rank):

curl "https://api.climatedata.dev/v1/us-climate/tavg/us-ia.json"

Open the JSON

What this can't tell you

A statewide average is not the average of its counties: NOAA computes it from its own grid, weighted by area.
The most recent months are preliminary and NOAA revises them in the next release.

How the answer is decided

Each month is ranked against the same month in every year on record (since 1895 for most places). The top tenth of the record is 'much warmer than normal', the top third 'warmer', the middle third 'near normal'. Counties are coloured by the same five words.

Sources

climatedata.dev us-climate, version 2026-10-25.6c7474e6d8 (U.S. public domain)
NOAA Monthly U.S. Climate Divisional Database (nClimDiv), statewide and national files (U.S. public domain)
climatedata.dev county-climate, version 2026-10-25.b4bbb5298a (U.S. public domain)
U.S. Census Bureau TIGERweb, counties (generalised) (U.S. public domain)
Built 2026-10-26. Download every county's answer (JSON)

Every topic for one county: How's Hennepin County?