Counties in Iowa by annual precipitation

Lee County had the highest annual precipitation of 99 counties in 2021, at 42.02 inches. Plymouth County had the lowest, at 24.06 inches. The median was 30.14 inches and the figure for Iowa was 30.84 inches. Source: NOAA National Centers for Environmental Information.

Keep it in a collection in your library.
Highest42.02Lee County
Lowest24.06Plymouth County
Median30.1499 counties
Iowa30.84History

Map of counties, 2021

Adair County: 32.2 inchesAdams County: 33.48 inchesAllamakee County: 31.57 inchesAppanoose County: 40.63 inchesAudubon County: 31.23 inchesBenton County: 26.45 inchesBlack Hawk County: 25.88 inchesBoone County: 27.71 inchesBremer County: 30.64 inchesBuchanan County: 29.24 inchesBuena Vista County: 28.03 inchesButler County: 28.51 inchesCalhoun County: 29.7 inchesCarroll County: 27.85 inchesCass County: 30.61 inchesCedar County: 30.17 inchesCerro Gordo County: 30.14 inchesCherokee County: 27.49 inchesChickasaw County: 36.45 inchesClarke County: 36.05 inchesClay County: 30.67 inchesClayton County: 29.6 inchesClinton County: 29.63 inchesCrawford County: 28.25 inchesDallas County: 27.89 inchesDavis County: 39.16 inchesDecatur County: 37.93 inchesDelaware County: 30.32 inchesDes Moines County: 41.39 inchesDickinson County: 28.79 inchesDubuque County: 27.53 inchesEmmet County: 28.07 inchesFayette County: 31.58 inchesFloyd County: 34.14 inchesFranklin County: 27.62 inchesFremont County: 33.87 inchesGreene County: 29.09 inchesGrundy County: 27.58 inchesGuthrie County: 30.06 inchesHamilton County: 26.87 inchesHancock County: 30.4 inchesHardin County: 26.54 inchesHarrison County: 33.3 inchesHenry County: 38.98 inchesHoward County: 34.16 inchesHumboldt County: 25.08 inchesIda County: 27.68 inchesIowa County: 29 inchesJackson County: 30.64 inchesJasper County: 28.55 inchesJefferson County: 36.17 inchesJohnson County: 30.33 inchesJones County: 29.05 inchesKeokuk County: 33.61 inchesKossuth County: 27.42 inchesLee County: 42.02 inchesLinn County: 29.27 inchesLouisa County: 37.28 inchesLucas County: 38.38 inchesLyon County: 28.6 inchesMadison County: 29.39 inchesMahaska County: 32.38 inchesMarion County: 31.94 inchesMarshall County: 25.86 inchesMills County: 33.3 inchesMitchell County: 34.69 inchesMonona County: 29.87 inchesMonroe County: 36.97 inchesMontgomery County: 33.32 inchesMuscatine County: 31.9 inchesO'Brien County: 29.57 inchesOsceola County: 28.1 inchesPage County: 34.3 inchesPalo Alto County: 29.36 inchesPlymouth County: 24.06 inchesPocahontas County: 28.13 inchesPolk County: 28.28 inchesPottawattamie County: 31.52 inchesPoweshiek County: 30.1 inchesRinggold County: 36.97 inchesSac County: 28.43 inchesScott County: 31.04 inchesShelby County: 29.92 inchesSioux County: 27.86 inchesStory County: 27.71 inchesTama County: 28.23 inchesTaylor County: 35.03 inchesUnion County: 35.76 inchesVan Buren County: 37.45 inchesWapello County: 36.37 inchesWarren County: 31.78 inchesWashington County: 34.58 inchesWayne County: 40.74 inchesWebster County: 26.84 inchesWinnebago County: 27.39 inchesWinneshiek County: 31.62 inchesWoodbury County: 25.72 inchesWorth County: 30.96 inchesWright County: 28.73 inches
  • Under 28
  • 28 to 29
  • 29 to 30
  • 30 to 32
  • 32 to 36
  • 36 and over
inches, 2021. Source: NOAA NCEI, NOAA Climate at a Glance, January to December precipitation, counties. Boundaries: U.S. Census Bureau cartographic boundary files.

Top 40 counties, 2021

Lee County: 42.02 inchesLee County42.02Des Moines County: 41.39 inchesDes Moines County41.39Wayne County: 40.74 inchesWayne County40.74Appanoose County: 40.63 inchesAppanoose County40.63Davis County: 39.16 inchesDavis County39.16Henry County: 38.98 inchesHenry County38.98Lucas County: 38.38 inchesLucas County38.38Decatur County: 37.93 inchesDecatur County37.93Van Buren County: 37.45 inchesVan Buren County37.45Louisa County: 37.28 inchesLouisa County37.28Monroe County: 36.97 inchesMonroe County36.97Ringgold County: 36.97 inchesRinggold County36.97Chickasaw County: 36.45 inchesChickasaw County36.45Wapello County: 36.37 inchesWapello County36.37Jefferson County: 36.17 inchesJefferson County36.17Clarke County: 36.05 inchesClarke County36.05Union County: 35.76 inchesUnion County35.76Taylor County: 35.03 inchesTaylor County35.03Mitchell County: 34.69 inchesMitchell County34.69Washington County: 34.58 inchesWashington County34.58Page County: 34.3 inchesPage County34.3Howard County: 34.16 inchesHoward County34.16Floyd County: 34.14 inchesFloyd County34.14Fremont County: 33.87 inchesFremont County33.87Keokuk County: 33.61 inchesKeokuk County33.61Adams County: 33.48 inchesAdams County33.48Montgomery County: 33.32 inchesMontgomery County33.32Harrison County: 33.3 inchesHarrison County33.3Mills County: 33.3 inchesMills County33.3Mahaska County: 32.38 inchesMahaska County32.38Adair County: 32.2 inchesAdair County32.2Marion County: 31.94 inchesMarion County31.94Muscatine County: 31.9 inchesMuscatine County31.9Warren County: 31.78 inchesWarren County31.78Winneshiek County: 31.62 inchesWinneshiek County31.62Fayette County: 31.58 inchesFayette County31.58Allamakee County: 31.57 inchesAllamakee County31.57Pottawattamie County: 31.52 inchesPottawattamie County31.52Audubon County: 31.23 inchesAudubon County31.23Scott County: 31.04 inchesScott County31.04Lee County: 42.02 inchesLee County42.02Des Moines County: 41.39 inchesDes Moines County41.39Wayne County: 40.74 inchesWayne County40.74Appanoose County: 40.63 inchesAppanoose County40.63Davis County: 39.16 inchesDavis County39.16Henry County: 38.98 inchesHenry County38.98Lucas County: 38.38 inchesLucas County38.38Decatur County: 37.93 inchesDecatur County37.93Van Buren County: 37.45 inchesVan Buren County37.45Louisa County: 37.28 inchesLouisa County37.28Monroe County: 36.97 inchesMonroe County36.97Ringgold County: 36.97 inchesRinggold County36.97Chickasaw County: 36.45 inchesChickasaw County36.45Wapello County: 36.37 inchesWapello County36.37Jefferson County: 36.17 inchesJefferson County36.17Clarke County: 36.05 inchesClarke County36.05Union County: 35.76 inchesUnion County35.76Taylor County: 35.03 inchesTaylor County35.03Mitchell County: 34.69 inchesMitchell County34.69Washington County: 34.58 inchesWashington County34.58Page County: 34.3 inchesPage County34.3Howard County: 34.16 inchesHoward County34.16Floyd County: 34.14 inchesFloyd County34.14Fremont County: 33.87 inchesFremont County33.87Keokuk County: 33.61 inchesKeokuk County33.61Adams County: 33.48 inchesAdams County33.48Montgomery County: 33.32 inchesMontgomery County33.32Harrison County: 33.3 inchesHarrison County33.3Mills County: 33.3 inchesMills County33.3Mahaska County: 32.38 inchesMahaska County32.38Adair County: 32.2 inchesAdair County32.2Marion County: 31.94 inchesMarion County31.94Muscatine County: 31.9 inchesMuscatine County31.9Warren County: 31.78 inchesWarren County31.78Winneshiek County: 31.62 inchesWinneshiek County31.62Fayette County: 31.58 inchesFayette County31.58Allamakee County: 31.57 inchesAllamakee County31.57Pottawattamie County: 31.52 inchesPottawattamie County31.52Audubon County: 31.23 inchesAudubon County31.23Scott County: 31.04 inchesScott County31.04
inches. Source: NOAA NCEI, NOAA Climate at a Glance, January to December precipitation, counties. Retrieved 2026-10-12.

Full ranking

RankCounties2021
inches
Change on 2020
1Lee County42.02+21.8%
2Des Moines County41.39+26.8%
3Wayne County40.74+21.6%
4Appanoose County40.63+17.6%
5Davis County39.16+12%
6Henry County38.98+13.4%
7Lucas County38.38+15.7%
8Decatur County37.93+18.1%
9Van Buren County37.45+13.5%
10Louisa County37.28+5.8%
11Monroe County36.97+4.8%
11Ringgold County36.97+12.7%
13Chickasaw County36.45+2%
14Wapello County36.37-1.3%
15Jefferson County36.17-0.2%
16Clarke County36.05+19.3%
17Union County35.76+27%
18Taylor County35.03+20%
19Mitchell County34.69+14.9%
20Washington County34.58-5.9%
21Page County34.3+39.9%
22Howard County34.16+4.7%
23Floyd County34.14+4.9%
24Fremont County33.87+40.3%
25Keokuk County33.61-2.9%
26Adams County33.48+26.1%
27Montgomery County33.32+35.3%
28Harrison County33.3+55.2%
28Mills County33.3+45.8%
30Mahaska County32.38-5.2%
31Adair County32.2+36%
32Marion County31.94-5.9%
33Muscatine County31.9-10.1%
34Warren County31.78-2.2%
35Winneshiek County31.62-9.4%
36Fayette County31.58-13.6%
37Allamakee County31.57-9.5%
38Pottawattamie County31.52+46.4%
39Audubon County31.23+46.2%
40Scott County31.04-20.8%
41Worth County30.96+1.8%
42Clay County30.67+48.2%
43Bremer County30.64-16.4%
43Jackson County30.64-20.3%
45Cass County30.61+39.6%
46Hancock County30.4+8.9%
47Johnson County30.33-15.1%
48Delaware County30.32-20.3%
49Cedar County30.17-21.7%
50Cerro Gordo County30.14+1.9%
51Poweshiek County30.1-8.4%
52Guthrie County30.06+34.9%
53Shelby County29.92+36.7%
54Monona County29.87+37.8%
55Calhoun County29.7+29.4%
56Clinton County29.63-24.1%
57Clayton County29.6-24.5%
58O'Brien County29.57+46.5%
59Madison County29.39+4.8%
60Palo Alto County29.36+31.4%
61Linn County29.27-20%
62Buchanan County29.24-20.8%
63Greene County29.09+25.7%
64Jones County29.05-21.2%
65Iowa County29-10.8%
66Dickinson County28.79+33.2%
67Wright County28.73+6.4%
68Lyon County28.6+52.9%
69Jasper County28.55-7.6%
70Butler County28.51-14.8%
71Sac County28.43+30.4%
72Polk County28.28-1.6%
73Crawford County28.25+24.8%
74Tama County28.23-18.7%
75Pocahontas County28.13+22.5%
76Osceola County28.1+39%
77Emmet County28.07+21.9%
78Buena Vista County28.03+22.5%
79Dallas County27.89+6.6%
80Sioux County27.86+59.2%
81Carroll County27.85+28.5%
82Boone County27.71+14.7%
82Story County27.71+6.2%
84Ida County27.68+19.3%
85Franklin County27.62-6.9%
86Grundy County27.58-21%
87Dubuque County27.53-28.6%
88Cherokee County27.49+18.7%
89Kossuth County27.42+7.4%
90Winnebago County27.39-2.6%
91Hamilton County26.87+5.5%
92Webster County26.84+9%
93Hardin County26.54-10.5%
94Benton County26.45-23.4%
95Black Hawk County25.88-29.5%
96Marshall County25.86-17.6%
97Woodbury County25.72+19%
98Humboldt County25.08-0.6%
99Plymouth County24.06+27.1%

Other periods

About this ranking

Total precipitation from January to December, in inches: rain plus the water content of snow and other frozen precipitation. 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, not the reading at one weather station. 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 precipitation, 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 precipitation, counties (Counties in Iowa by annual precipitation, 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 precipitation, counties, Counties in Iowa by annual precipitation, 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/annual-precipitation/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 precipitation, counties. Counties in Iowa by annual precipitation, 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/annual-precipitation/iowa-counties?period=2021.

Harvard

NOAA National Centers for Environmental Information (2026) NOAA Climate at a Glance, January to December precipitation, counties, Counties in Iowa by annual precipitation, 2021 [Dataset]. Available at: https://www.ncei.noaa.gov/access/monitoring/climate-at-a-glance/county/mapping, via Invokely: https://invokely.ai/rankings/annual-precipitation/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 precipitation, counties: Counties in Iowa by annual precipitation, 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/annual-precipitation/iowa-counties?period=2021. Publisher attribution: NOAA National Centers for Environmental Information, Climate at a Glance. NOAA Climate at a Glance, January to December precipitation, 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 precipitation, counties: Counties in Iowa by annual precipitation, 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/annual-precipitation/iowa-counties?period=2021
Y2  - 2026/10/12
N1  - Accessed via Invokely, https://invokely.ai/rankings/annual-precipitation/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 precipitation, 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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Rank Counties in Iowa by annual precipitation using official data, and cite the source.
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Questions

Which county has the highest annual precipitation?

Lee County, with 42.02 inches in 2021, according to NOAA National Centers for Environmental Information.

Which county has the lowest annual precipitation?

Plymouth County, with 24.06 inches 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 precipitation, counties. Retrieved 2026-10-12.

Annual precipitation: other rankings

Counties in Iowa: more rankings