Counties in Iowa by annual precipitation

Fayette County had the highest annual precipitation of 99 counties in 2017, at 40.77 inches. Keokuk County had the lowest, at 25.05 inches. The median was 32.06 inches and the figure for Iowa was 32.35 inches. Source: NOAA National Centers for Environmental Information.

Keep it in a collection in your library.
Highest40.77Fayette County
Lowest25.05Keokuk County
Median32.0699 counties
Iowa32.35History

Map of counties, 2017

Adair County: 36.03 inchesAdams County: 33.7 inchesAllamakee County: 36.49 inchesAppanoose County: 31.71 inchesAudubon County: 37.28 inchesBenton County: 27.44 inchesBlack Hawk County: 31.64 inchesBoone County: 31.57 inchesBremer County: 38.26 inchesBuchanan County: 33.49 inchesBuena Vista County: 27.07 inchesButler County: 34.58 inchesCalhoun County: 29.86 inchesCarroll County: 33.23 inchesCass County: 35.1 inchesCedar County: 32.66 inchesCerro Gordo County: 32.09 inchesCherokee County: 27.13 inchesChickasaw County: 40.22 inchesClarke County: 29.43 inchesClay County: 32.26 inchesClayton County: 38.56 inchesClinton County: 36.69 inchesCrawford County: 39.44 inchesDallas County: 32.18 inchesDavis County: 29.01 inchesDecatur County: 30.94 inchesDelaware County: 36.37 inchesDes Moines County: 31.65 inchesDickinson County: 33.81 inchesDubuque County: 38.16 inchesEmmet County: 30.36 inchesFayette County: 40.77 inchesFloyd County: 37.48 inchesFranklin County: 34.35 inchesFremont County: 34.66 inchesGreene County: 30.99 inchesGrundy County: 31.8 inchesGuthrie County: 35.98 inchesHamilton County: 32.69 inchesHancock County: 29.92 inchesHardin County: 32.47 inchesHarrison County: 33.96 inchesHenry County: 31.2 inchesHoward County: 36.47 inchesHumboldt County: 30.01 inchesIda County: 32.38 inchesIowa County: 27.11 inchesJackson County: 35.75 inchesJasper County: 28.5 inchesJefferson County: 28.55 inchesJohnson County: 30.35 inchesJones County: 36.15 inchesKeokuk County: 25.05 inchesKossuth County: 29.68 inchesLee County: 30.18 inchesLinn County: 31.24 inchesLouisa County: 32.73 inchesLucas County: 33.5 inchesLyon County: 27.44 inchesMadison County: 31.07 inchesMahaska County: 25.29 inchesMarion County: 28.67 inchesMarshall County: 29.18 inchesMills County: 33.5 inchesMitchell County: 35.5 inchesMonona County: 34.14 inchesMonroe County: 29.54 inchesMontgomery County: 34.76 inchesMuscatine County: 34.56 inchesO'Brien County: 30.37 inchesOsceola County: 30.44 inchesPage County: 35.63 inchesPalo Alto County: 29.23 inchesPlymouth County: 29.88 inchesPocahontas County: 29.29 inchesPolk County: 31.9 inchesPottawattamie County: 32.3 inchesPoweshiek County: 28.39 inchesRinggold County: 32.06 inchesSac County: 30.8 inchesScott County: 37.33 inchesShelby County: 37.62 inchesSioux County: 30.12 inchesStory County: 32.39 inchesTama County: 28.59 inchesTaylor County: 35.99 inchesUnion County: 30.51 inchesVan Buren County: 28.79 inchesWapello County: 26.38 inchesWarren County: 29.16 inchesWashington County: 30.98 inchesWayne County: 33.06 inchesWebster County: 30.48 inchesWinnebago County: 30.03 inchesWinneshiek County: 35.97 inchesWoodbury County: 32.06 inchesWorth County: 32.66 inchesWright County: 32.18 inches
  • Under 29
  • 29 to 30
  • 30 to 32
  • 32 to 34
  • 34 to 36
  • 36 and over
inches, 2017. Source: NOAA NCEI, NOAA Climate at a Glance, January to December precipitation, counties. Boundaries: U.S. Census Bureau cartographic boundary files.

Top 40 counties, 2017

Fayette County: 40.77 inchesFayette County40.77Chickasaw County: 40.22 inchesChickasaw County40.22Crawford County: 39.44 inchesCrawford County39.44Clayton County: 38.56 inchesClayton County38.56Bremer County: 38.26 inchesBremer County38.26Dubuque County: 38.16 inchesDubuque County38.16Shelby County: 37.62 inchesShelby County37.62Floyd County: 37.48 inchesFloyd County37.48Scott County: 37.33 inchesScott County37.33Audubon County: 37.28 inchesAudubon County37.28Clinton County: 36.69 inchesClinton County36.69Allamakee County: 36.49 inchesAllamakee County36.49Howard County: 36.47 inchesHoward County36.47Delaware County: 36.37 inchesDelaware County36.37Jones County: 36.15 inchesJones County36.15Adair County: 36.03 inchesAdair County36.03Taylor County: 35.99 inchesTaylor County35.99Guthrie County: 35.98 inchesGuthrie County35.98Winneshiek County: 35.97 inchesWinneshiek County35.97Jackson County: 35.75 inchesJackson County35.75Page County: 35.63 inchesPage County35.63Mitchell County: 35.5 inchesMitchell County35.5Cass County: 35.1 inchesCass County35.1Montgomery County: 34.76 inchesMontgomery County34.76Fremont County: 34.66 inchesFremont County34.66Butler County: 34.58 inchesButler County34.58Muscatine County: 34.56 inchesMuscatine County34.56Franklin County: 34.35 inchesFranklin County34.35Monona County: 34.14 inchesMonona County34.14Harrison County: 33.96 inchesHarrison County33.96Dickinson County: 33.81 inchesDickinson County33.81Adams County: 33.7 inchesAdams County33.7Lucas County: 33.5 inchesLucas County33.5Mills County: 33.5 inchesMills County33.5Buchanan County: 33.49 inchesBuchanan County33.49Carroll County: 33.23 inchesCarroll County33.23Wayne County: 33.06 inchesWayne County33.06Louisa County: 32.73 inchesLouisa County32.73Hamilton County: 32.69 inchesHamilton County32.69Cedar County: 32.66 inchesCedar County32.66Fayette County: 40.77 inchesFayette County40.77Chickasaw County: 40.22 inchesChickasaw County40.22Crawford County: 39.44 inchesCrawford County39.44Clayton County: 38.56 inchesClayton County38.56Bremer County: 38.26 inchesBremer County38.26Dubuque County: 38.16 inchesDubuque County38.16Shelby County: 37.62 inchesShelby County37.62Floyd County: 37.48 inchesFloyd County37.48Scott County: 37.33 inchesScott County37.33Audubon County: 37.28 inchesAudubon County37.28Clinton County: 36.69 inchesClinton County36.69Allamakee County: 36.49 inchesAllamakee County36.49Howard County: 36.47 inchesHoward County36.47Delaware County: 36.37 inchesDelaware County36.37Jones County: 36.15 inchesJones County36.15Adair County: 36.03 inchesAdair County36.03Taylor County: 35.99 inchesTaylor County35.99Guthrie County: 35.98 inchesGuthrie County35.98Winneshiek County: 35.97 inchesWinneshiek County35.97Jackson County: 35.75 inchesJackson County35.75Page County: 35.63 inchesPage County35.63Mitchell County: 35.5 inchesMitchell County35.5Cass County: 35.1 inchesCass County35.1Montgomery County: 34.76 inchesMontgomery County34.76Fremont County: 34.66 inchesFremont County34.66Butler County: 34.58 inchesButler County34.58Muscatine County: 34.56 inchesMuscatine County34.56Franklin County: 34.35 inchesFranklin County34.35Monona County: 34.14 inchesMonona County34.14Harrison County: 33.96 inchesHarrison County33.96Dickinson County: 33.81 inchesDickinson County33.81Adams County: 33.7 inchesAdams County33.7Lucas County: 33.5 inchesLucas County33.5Mills County: 33.5 inchesMills County33.5Buchanan County: 33.49 inchesBuchanan County33.49Carroll County: 33.23 inchesCarroll County33.23Wayne County: 33.06 inchesWayne County33.06Louisa County: 32.73 inchesLouisa County32.73Hamilton County: 32.69 inchesHamilton County32.69Cedar County: 32.66 inchesCedar County32.66
inches. Source: NOAA NCEI, NOAA Climate at a Glance, January to December precipitation, counties. Retrieved 2026-10-12.

Full ranking

RankCounties2017
inches
Change on 2016
1Fayette County40.77-9.9%
2Chickasaw County40.22-23.4%
3Crawford County39.44+12.6%
4Clayton County38.56-14%
5Bremer County38.26-16.2%
6Dubuque County38.16-10.8%
7Shelby County37.62+1.3%
8Floyd County37.48-29.1%
9Scott County37.33-8.3%
10Audubon County37.28-3.4%
11Clinton County36.69-9.9%
12Allamakee County36.49-31%
13Howard County36.47-32.2%
14Delaware County36.37-13.6%
15Jones County36.15-13.6%
16Adair County36.03-2.8%
17Taylor County35.99-14%
18Guthrie County35.98-1.1%
19Winneshiek County35.97-34.4%
20Jackson County35.75-10.5%
21Page County35.63-16.8%
22Mitchell County35.5-31.3%
23Cass County35.1-8.1%
24Montgomery County34.76-18.4%
25Fremont County34.66-15.1%
26Butler County34.58-23.5%
27Muscatine County34.56-2.3%
28Franklin County34.35-20%
29Monona County34.14+6.1%
30Harrison County33.96-4.4%
31Dickinson County33.81-14.8%
32Adams County33.7-13.7%
33Lucas County33.5+12.7%
33Mills County33.5-16%
35Buchanan County33.49-20.7%
36Carroll County33.23-8.4%
37Wayne County33.06+13.9%
38Louisa County32.73-11.4%
39Hamilton County32.69-14.3%
40Cedar County32.66-16.6%
40Worth County32.66-32.5%
42Hardin County32.47-14.5%
43Story County32.39-16.7%
44Ida County32.38-7.1%
45Pottawattamie County32.3-13%
46Clay County32.26-21.7%
47Dallas County32.18-9.3%
47Wright County32.18-16.1%
49Cerro Gordo County32.09-31.2%
50Ringgold County32.06-11%
50Woodbury County32.06-0.5%
52Polk County31.9-12.1%
53Grundy County31.8-16.2%
54Appanoose County31.71+12.2%
55Des Moines County31.65-11.9%
56Black Hawk County31.64-24%
57Boone County31.57-19.6%
58Linn County31.24-25.3%
59Henry County31.2-6.3%
60Madison County31.07-5.9%
61Greene County30.99-18.5%
62Washington County30.98-4%
63Decatur County30.94+2.4%
64Sac County30.8-11.1%
65Union County30.51-14%
66Webster County30.48-20.8%
67Osceola County30.44-21.3%
68O'Brien County30.37-21.9%
69Emmet County30.36-14.2%
70Johnson County30.35-17.3%
71Lee County30.18-5.3%
72Sioux County30.12-12.5%
73Winnebago County30.03-34.5%
74Humboldt County30.01-13.5%
75Hancock County29.92-31.5%
76Plymouth County29.88-10.4%
77Calhoun County29.86-16.3%
78Kossuth County29.68-22.8%
79Monroe County29.54+11.7%
80Clarke County29.43-7.7%
81Pocahontas County29.29-18.7%
82Palo Alto County29.23-22%
83Marshall County29.18-19.1%
84Warren County29.16-14%
85Davis County29.01-3.2%
86Van Buren County28.79-4.9%
87Marion County28.67-12.3%
88Tama County28.59-18.7%
89Jefferson County28.55-10.1%
90Jasper County28.5-17%
91Poweshiek County28.39-19.3%
92Benton County27.44-30.3%
92Lyon County27.44-20%
94Cherokee County27.13-26.3%
95Iowa County27.11-24%
96Buena Vista County27.07-27.2%
97Wapello County26.38-2.8%
98Mahaska County25.29-17.8%
99Keokuk County25.05-20.1%

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, 2017) [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, 2017. 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=2017. 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, 2017. 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=2017.

Harvard

NOAA National Centers for Environmental Information (2026) NOAA Climate at a Glance, January to December precipitation, counties, Counties in Iowa by annual precipitation, 2017 [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=2017 (Accessed: 12 October 2026).

BibTeX
@misc{noaa_counties_in_iowa_by_2017,
  author = {{NOAA National Centers for Environmental Information}},
  title = {{NOAA Climate at a Glance, January to December precipitation, counties: Counties in Iowa by annual precipitation, 2017}},
  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=2017. 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, 2017
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=2017
Y2  - 2026/10/12
N1  - Accessed via Invokely, https://invokely.ai/rankings/annual-precipitation/iowa-counties?period=2017.
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?

Fayette County, with 40.77 inches in 2017, according to NOAA National Centers for Environmental Information.

Which county has the lowest annual precipitation?

Keokuk County, with 25.05 inches in 2017.

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