Counties in Iowa by average annual temperature

Fremont County had the highest average annual temperature of 99 counties in 2021, at 53.1 °F. Howard County had the lowest, at 46.7 °F. The median was 50.2 °F and the figure for Iowa was 50 °F. Source: NOAA National Centers for Environmental Information.

Highest53.1Fremont County

Lowest46.7Howard County

Median50.299 counties

Iowa50History

Map of counties, 2021

Under 48
48 to 49
49 to 50
50 to 51
51 to 52
52 and over

°F, 2021. Source: NOAA NCEI, NOAA Climate at a Glance, January to December average temperature, counties. Boundaries: U.S. Census Bureau cartographic boundary files.

Top 40 counties, 2021

°F. Source: NOAA NCEI, NOAA Climate at a Glance, January to December average temperature, counties. Retrieved 2026-10-12.

Full ranking

Rank	Counties	2021 °F	Change on 2020
1	Fremont County	53.1	+1.3%
2	Page County	52.8	+1.3%
3	Lee County	52.7	+1.2%
4	Mills County	52.6	+1.3%
5	Decatur County	52.4	+1.7%
6	Des Moines County	52.3	+1%
7	Taylor County	52.2	+1.6%
8	Davis County	52.1	+1.6%
8	Louisa County	52.1	+1.2%
8	Ringgold County	52.1	+1.8%
11	Appanoose County	52	+1.4%
12	Clarke County	51.9	+1.6%
12	Montgomery County	51.9	+1%
12	Pottawattamie County	51.9	+1.8%
12	Wapello County	51.9	+2%
16	Monroe County	51.8	+1.4%
16	Wayne County	51.8	+1.4%
18	Harrison County	51.7	+2.2%
18	Lucas County	51.7	+1.4%
18	Scott County	51.7	+1.2%
18	Van Buren County	51.7	+1.6%
18	Warren County	51.7	+1.2%
23	Henry County	51.6	+1.2%
24	Polk County	51.5	+2%
25	Mahaska County	51.4	+1.6%
25	Marion County	51.4	+1.6%
27	Dallas County	51.3	+1.8%
28	Adams County	51.2	+1.2%
28	Clinton County	51.2	+1%
28	Jefferson County	51.2	+2%
28	Madison County	51.2	+1.4%
28	Washington County	51.2	+1.4%
33	Keokuk County	51.1	+1.4%
33	Union County	51.1	+1.2%
35	Jasper County	51	+1.6%
36	Cass County	50.9	+1.2%
36	Monona County	50.9	+2%
36	Muscatine County	50.9	+1%
39	Shelby County	50.7	+1.6%
40	Boone County	50.6	+1.8%
41	Crawford County	50.5	+2%
42	Greene County	50.4	+1.8%
42	Poweshiek County	50.4	+1%
42	Story County	50.4	+1.8%
45	Adair County	50.3	+0.8%
45	Carroll County	50.3	+1.6%
45	Guthrie County	50.3	+0.6%
45	Johnson County	50.3	+1.4%
49	Iowa County	50.2	+0.8%
49	Jackson County	50.2	+1%
51	Cedar County	50.1	+1.2%
51	Woodbury County	50.1	+1.4%
53	Audubon County	49.9	+1%
53	Marshall County	49.9	+1.4%
53	Sac County	49.9	+1.8%
56	Calhoun County	49.8	+1.8%
56	Jones County	49.8	+1.4%
58	Ida County	49.7	+1.8%
58	Plymouth County	49.7	+2.1%
60	Linn County	49.6	+2.1%
61	Tama County	49.5	+1.4%
62	Black Hawk County	49.4	+1.9%
62	Webster County	49.4	+2.1%
64	Hardin County	49.3	+1.9%
65	Benton County	49.2	+2.5%
65	Grundy County	49.2	+1.7%
67	Hamilton County	49.1	+2.1%
68	Humboldt County	49	+2.3%
69	Cherokee County	48.9	+1.7%
70	Buena Vista County	48.8	+1.7%
70	Butler County	48.8	+1.9%
70	Dubuque County	48.8	+1.5%
73	Pocahontas County	48.7	+1.9%
73	Sioux County	48.7	+2.3%
75	Bremer County	48.6	+1.9%
75	Franklin County	48.6	+1.9%
77	Buchanan County	48.4	+2.5%
77	O'Brien County	48.4	+2.1%
77	Wright County	48.4	+2.1%
80	Clay County	48.3	+1.7%
80	Delaware County	48.3	+1.5%
82	Clayton County	48.2	+1.7%
82	Floyd County	48.2	+2.6%
82	Lyon County	48.2	+2.6%
82	Palo Alto County	48.2	+2.1%
86	Kossuth County	48.1	+2.3%
87	Cerro Gordo County	48	+2.3%
88	Allamakee County	47.9	+1.7%
88	Hancock County	47.9	+2.1%
90	Winneshiek County	47.8	+1.9%
91	Chickasaw County	47.7	+2.6%
92	Dickinson County	47.6	+2.1%
92	Fayette County	47.6	+2.1%
92	Osceola County	47.6	+2.6%
95	Emmet County	47.4	+2.6%
95	Mitchell County	47.4	+2.8%
97	Winnebago County	47.3	+2.4%
97	Worth County	47.3	+2.8%
99	Howard County	46.7	+2.6%

Other periods

About this ranking

Mean air temperature from January to December, in degrees Fahrenheit: the average of the 12 monthly mean temperatures. NOAA computes it from its climate divisional dataset (nClimDiv): station readings interpolated onto a 5 km grid and averaged over the area.

Values are area averages, so a county with mountains and valleys has one value for very different local climates. NOAA revises the last two years every month.

Every value in the ranking comes from the same publisher and the same period, so the counties are compared on one definition. Equal values share a rank.

How to cite

NOAA National Centers for Environmental Information, Climate at a Glance. NOAA Climate at a Glance, January to December average temperature, counties. From the NOAA Monthly U.S. Climate Divisional Database (nClimDiv), doi:10.7289/V5M32STR. https://www.ncei.noaa.gov/access/monitoring/climate-at-a-glance/county/mapping. Retrieved 2026-10-12.

Citation styles

The publisher is the author. Invokely is named only as the place the figures were read, where a style asks for it.

APA 7

NOAA National Centers for Environmental Information. (2026). NOAA Climate at a Glance, January to December average temperature, counties (Counties in Iowa by average annual temperature, 2021) [Data set]. Retrieved October 12, 2026, from https://www.ncei.noaa.gov/access/monitoring/climate-at-a-glance/county/mapping

MLA 9

NOAA Climate at a Glance, January to December average temperature, counties, Counties in Iowa by average annual temperature, 2021. NOAA National Centers for Environmental Information, 6 Oct. 2026, https://www.ncei.noaa.gov/access/monitoring/climate-at-a-glance/county/mapping. Invokely, https://invokely.ai/rankings/average-annual-temperature/iowa-counties?period=2021. Accessed 12 Oct. 2026.

Chicago (author-date)

NOAA National Centers for Environmental Information. 2026. NOAA Climate at a Glance, January to December average temperature, counties. Counties in Iowa by average annual temperature, 2021. Dataset. Accessed October 12, 2026. https://www.ncei.noaa.gov/access/monitoring/climate-at-a-glance/county/mapping. Also distributed by Invokely, https://invokely.ai/rankings/average-annual-temperature/iowa-counties?period=2021.

Harvard

NOAA National Centers for Environmental Information (2026) NOAA Climate at a Glance, January to December average temperature, counties, Counties in Iowa by average annual temperature, 2021 [Dataset]. Available at: https://www.ncei.noaa.gov/access/monitoring/climate-at-a-glance/county/mapping, via Invokely: https://invokely.ai/rankings/average-annual-temperature/iowa-counties?period=2021 (Accessed: 12 October 2026).

BibTeX

@misc{noaa_counties_in_iowa_by_2021,
  author = {{NOAA National Centers for Environmental Information}},
  title = {{NOAA Climate at a Glance, January to December average temperature, counties: Counties in Iowa by average annual temperature, 2021}},
  year = {2026},
  howpublished = {Data set},
  url = {https://www.ncei.noaa.gov/access/monitoring/climate-at-a-glance/county/mapping},
  urldate = {2026-10-12},
  note = {Accessed via Invokely, https://invokely.ai/rankings/average-annual-temperature/iowa-counties?period=2021. Publisher attribution: NOAA National Centers for Environmental Information, Climate at a Glance. NOAA Climate at a Glance, January to December average temperature, counties. From the NOAA Monthly U.S. Climate Divisional Database (nClimDiv), doi:10.7289/V5M32STR. https://www.ncei.noaa.gov/access/monitoring/climate-at-a-glance/county/mapping. Retrieved 2026-10-12.},
}

RIS

TY  - DATA
AU  - NOAA National Centers for Environmental Information
TI  - NOAA Climate at a Glance, January to December average temperature, counties: Counties in Iowa by average annual temperature, 2021
PY  - 2026
DA  - 2026/10/06
PB  - NOAA National Centers for Environmental Information
DB  - Invokely
UR  - https://www.ncei.noaa.gov/access/monitoring/climate-at-a-glance/county/mapping
L2  - https://invokely.ai/rankings/average-annual-temperature/iowa-counties?period=2021
Y2  - 2026/10/12
N1  - Accessed via Invokely, https://invokely.ai/rankings/average-annual-temperature/iowa-counties?period=2021.
N1  - Publisher attribution: NOAA National Centers for Environmental Information, Climate at a Glance. NOAA Climate at a Glance, January to December average temperature, counties. From the NOAA Monthly U.S. Climate Divisional Database (nClimDiv), doi:10.7289/V5M32STR. https://www.ncei.noaa.gov/access/monitoring/climate-at-a-glance/county/mapping. Retrieved 2026-10-12.
ER  -

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Questions

Which county has the highest average annual temperature?

Fremont County, with 53.1 °F in 2021, according to NOAA National Centers for Environmental Information.

Which county has the lowest average annual temperature?

Howard County, with 46.7 °F in 2021.

Where does this ranking come from?

Every value comes from one source and one period, so the places are comparable: NOAA National Centers for Environmental Information, NOAA Climate at a Glance, January to December average temperature, counties. Retrieved 2026-10-12.