Wonders

El Niño 2026 in Wisconsin: what it could do in your county, and what to do

In 1997–98, 44 of 72 Wisconsin counties got more December–February rain than normal, and the median one got 103%. In 2015–16, 72 did, and the median got 150% (Vose et al., 2014b). Here is every county, and a plan for yours.

By Wonders · September 24, 2026 · Data retrieved September 24, 2026

NOAA puts it at three chances in four (75%) that by October–December this is the strongest El Niño in its index record, which goes back to 1950 (Climate Prediction Center, 2026b). A new National Flood Insurance Program policy usually takes effect 30 days after you buy it, so buy it at least a month before the storms (FloodSmart, n.d.).

The full story, the research behind it and who is working on it now are in the main post.

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Wisconsin, county by county

How many of the seven strongest El Niño winters since 1950 brought heavier winter rain than each county’s 1991–2020 normal (Climate Prediction Center, 2026a; Vose et al., 2014b); heavier rain is what came with the flood and storm disasters listed below. 38 of 72 were wetter in five or more; 1 in two or fewer.

Racine County: heavier winter rain than normal in 4 of the 7 strongest El Niño winters on record, and 1 federal flood or storm disaster in themRichland County: heavier winter rain than normal in 5 of the 7 strongest El Niño winters on recordRock County: heavier winter rain than normal in 2 of the 7 strongest El Niño winters on record, and 1 federal flood or storm disaster in themRusk County: heavier winter rain than normal in 5 of the 7 strongest El Niño winters on record, and 1 federal flood or storm disaster in themSt. Croix County: heavier winter rain than normal in 5 of the 7 strongest El Niño winters on recordSauk County: heavier winter rain than normal in 5 of the 7 strongest El Niño winters on recordSawyer County: heavier winter rain than normal in 5 of the 7 strongest El Niño winters on recordShawano County: heavier winter rain than normal in 5 of the 7 strongest El Niño winters on recordSheboygan County: heavier winter rain than normal in 4 of the 7 strongest El Niño winters on record, and 1 federal flood or storm disaster in themTaylor County: heavier winter rain than normal in 5 of the 7 strongest El Niño winters on recordTrempealeau County: heavier winter rain than normal in 5 of the 7 strongest El Niño winters on recordVernon County: heavier winter rain than normal in 4 of the 7 strongest El Niño winters on recordVilas County: heavier winter rain than normal in 3 of the 7 strongest El Niño winters on recordWalworth County: heavier winter rain than normal in 3 of the 7 strongest El Niño winters on record, and 1 federal flood or storm disaster in themWashburn County: heavier winter rain than normal in 5 of the 7 strongest El Niño winters on recordWashington County: heavier winter rain than normal in 5 of the 7 strongest El Niño winters on recordWaukesha County: heavier winter rain than normal in 4 of the 7 strongest El Niño winters on record, and 1 federal flood or storm disaster in themWaupaca County: heavier winter rain than normal in 5 of the 7 strongest El Niño winters on record, and 1 federal flood or storm disaster in themWaushara County: heavier winter rain than normal in 5 of the 7 strongest El Niño winters on record, and 1 federal flood or storm disaster in themWinnebago County: heavier winter rain than normal in 4 of the 7 strongest El Niño winters on recordWood County: heavier winter rain than normal in 4 of the 7 strongest El Niño winters on record, and 1 federal flood or storm disaster in themMarinette County: heavier winter rain than normal in 3 of the 7 strongest El Niño winters on record, and 1 federal flood or storm disaster in themManitowoc County: heavier winter rain than normal in 4 of the 7 strongest El Niño winters on record, and 1 federal flood or storm disaster in themLincoln County: heavier winter rain than normal in 3 of the 7 strongest El Niño winters on record, and 1 federal flood or storm disaster in themMarathon County: heavier winter rain than normal in 5 of the 7 strongest El Niño winters on record, and 1 federal flood or storm disaster in themClark County: heavier winter rain than normal in 5 of the 7 strongest El Niño winters on record, and 1 federal flood or storm disaster in themPortage County: heavier winter rain than normal in 5 of the 7 strongest El Niño winters on record, and 1 federal flood or storm disaster in themMenominee County: heavier winter rain than normal in 5 of the 7 strongest El Niño winters on recordGreen Lake County: heavier winter rain than normal in 5 of the 7 strongest El Niño winters on record, and 1 federal flood or storm disaster in themKenosha County: heavier winter rain than normal in 3 of the 7 strongest El Niño winters on record, and 1 federal flood or storm disaster in themMarquette County: heavier winter rain than normal in 5 of the 7 strongest El Niño winters on record, and 1 federal flood or storm disaster in themPrice County: heavier winter rain than normal in 4 of the 7 strongest El Niño winters on recordLanglade County: heavier winter rain than normal in 5 of the 7 strongest El Niño winters on record, and 1 federal flood or storm disaster in themChippewa County: heavier winter rain than normal in 5 of the 7 strongest El Niño winters on record, and 1 federal flood or storm disaster in themBayfield County: heavier winter rain than normal in 4 of the 7 strongest El Niño winters on recordFlorence County: heavier winter rain than normal in 3 of the 7 strongest El Niño winters on recordOzaukee County: heavier winter rain than normal in 5 of the 7 strongest El Niño winters on record, and 1 federal flood or storm disaster in themDodge County: heavier winter rain than normal in 4 of the 7 strongest El Niño winters on recordPierce County: heavier winter rain than normal in 5 of the 7 strongest El Niño winters on recordPolk County: heavier winter rain than normal in 4 of the 7 strongest El Niño winters on recordColumbia County: heavier winter rain than normal in 4 of the 7 strongest El Niño winters on recordPepin County: heavier winter rain than normal in 5 of the 7 strongest El Niño winters on record, and 1 federal flood or storm disaster in themCalumet County: heavier winter rain than normal in 4 of the 7 strongest El Niño winters on recordOutagamie County: heavier winter rain than normal in 4 of the 7 strongest El Niño winters on record, and 1 federal flood or storm disaster in themBuffalo County: heavier winter rain than normal in 5 of the 7 strongest El Niño winters on record, and 1 federal flood or storm disaster in themBarron County: heavier winter rain than normal in 5 of the 7 strongest El Niño winters on recordKewaunee County: heavier winter rain than normal in 4 of the 7 strongest El Niño winters on record, and 1 federal flood or storm disaster in themIron County: heavier winter rain than normal in 3 of the 7 strongest El Niño winters on recordCrawford County: heavier winter rain than normal in 5 of the 7 strongest El Niño winters on record, and 1 federal flood or storm disaster in themBurnett County: heavier winter rain than normal in 5 of the 7 strongest El Niño winters on recordDane County: heavier winter rain than normal in 4 of the 7 strongest El Niño winters on recordDouglas County: heavier winter rain than normal in 4 of the 7 strongest El Niño winters on recordGrant County: heavier winter rain than normal in 5 of the 7 strongest El Niño winters on recordLa Crosse County: heavier winter rain than normal in 5 of the 7 strongest El Niño winters on record, and 1 federal flood or storm disaster in themEau Claire County: heavier winter rain than normal in 5 of the 7 strongest El Niño winters on record, and 1 federal flood or storm disaster in themMilwaukee County: heavier winter rain than normal in 4 of the 7 strongest El Niño winters on record, and 1 federal flood or storm disaster in themJackson County: heavier winter rain than normal in 5 of the 7 strongest El Niño winters on recordDoor County: heavier winter rain than normal in 3 of the 7 strongest El Niño winters on record, and 1 federal flood or storm disaster in themOconto County: heavier winter rain than normal in 3 of the 7 strongest El Niño winters on record, and 1 federal flood or storm disaster in themLafayette County: heavier winter rain than normal in 5 of the 7 strongest El Niño winters on recordGreen County: heavier winter rain than normal in 5 of the 7 strongest El Niño winters on recordDunn County: heavier winter rain than normal in 5 of the 7 strongest El Niño winters on record, and 1 federal flood or storm disaster in themFond du Lac County: heavier winter rain than normal in 4 of the 7 strongest El Niño winters on recordAshland County: heavier winter rain than normal in 4 of the 7 strongest El Niño winters on recordAdams County: heavier winter rain than normal in 5 of the 7 strongest El Niño winters on recordJefferson County: heavier winter rain than normal in 4 of the 7 strongest El Niño winters on record, and 1 federal flood or storm disaster in themOneida County: heavier winter rain than normal in 3 of the 7 strongest El Niño winters on recordMonroe County: heavier winter rain than normal in 5 of the 7 strongest El Niño winters on recordForest County: heavier winter rain than normal in 3 of the 7 strongest El Niño winters on recordJuneau County: heavier winter rain than normal in 5 of the 7 strongest El Niño winters on recordBrown County: heavier winter rain than normal in 4 of the 7 strongest El Niño winters on record, and 1 federal flood or storm disaster in themIowa County: heavier winter rain than normal in 5 of the 7 strongest El Niño winters on record
  • 0–1 of 7 lighter winter rain in most
  • 2 of 7 lighter more often
  • 3–4 of 7 no clear pattern
  • 5 of 7 heavier winter rain more often
  • 6–7 of 7 heavier winter rain in most

Federal disasters declared in those winters

In the 6 strong El Niño winters since 1965–66, 1 federal weather disaster declaration, recorded by FEMA, covered 34 of Wisconsin's 72 counties (Federal Emergency Management Agency, 2026). Across all its counties, that is 34 designations in 6 winters, or 5.7 a winter, against 2.3 a winter in the other 55.

  • 1972–73Severe storms & flooding DR-376Flood · 34 counties

A declaration means damage large enough for federal aid, so these undercount smaller floods and storms. Declarations have also become more common over the decades, which weighs the comparison toward the recent winters.

What to do before the storms

  • A new National Flood Insurance Program policy usually takes effect 30 days after you buy it, so buy it at least a month before the storms (FloodSmart, n.d.).
  • Six inches of fast-moving water can knock over an adult, and 12 inches can carry away most cars. More than half of flood drownings happen when a vehicle is driven into flood water (National Weather Service, n.d.-c).
  • Before the fire season, clear leaves, debris and anything flammable for at least 30 feet around your home (Ready.gov, n.d.-c).
  • After a wildfire, flood risk stays significantly higher for up to five years, until plants grow back (Federal Emergency Management Agency, n.d.).

Every county

December–February rain as a share of the 1991–2020 normal, and federal weather disaster designations in the strong winters since 1965–66.

CountyWetter
(of 7)
1997–9897–982015–1615–16Normal
(in)
FEMA
Adams CountyAdams5102%184%3.98—
Ashland CountyAshland483%147%4.03—
Barron CountyBarron5104%139%3.16—
Bayfield CountyBayfield488%163%3.65—
Brown CountyBrown494%178%4.501
Buffalo CountyBuffalo5135%151%3.531
Burnett CountyBurnett5106%107%2.88—
Calumet CountyCalumet499%172%4.26—
Chippewa CountyChippewa5116%137%3.321
Clark CountyClark5105%166%3.511
Columbia CountyColumbia498%133%4.23—
Crawford CountyCrawford5108%178%3.901
Dane CountyDane498%115%4.57—
Dodge CountyDodge496%128%4.35—
Door CountyDoor394%170%4.831
Douglas CountyDouglas4106%139%3.23—
Dunn CountyDunn5119%141%3.451
Eau Claire CountyEau Claire5119%147%3.571
Florence CountyFlorence3100%146%3.72—
Fond du Lac CountyFond du Lac495%156%4.02—
Forest CountyForest399%144%3.87—
Grant CountyGrant5101%149%4.22—
Green CountyGreen5101%115%4.86—
Green Lake CountyGreen Lake5109%158%4.011
Iowa CountyIowa5115%149%4.27—
Iron CountyIron379%150%4.59—
Jackson CountyJackson5115%171%3.57—
Jefferson CountyJefferson494%121%4.761
Juneau CountyJuneau5102%187%3.94—
Kenosha CountyKenosha399%111%5.381
Kewaunee CountyKewaunee490%174%4.631
La Crosse CountyLa Crosse5133%187%3.711
Lafayette CountyLafayette5108%125%4.54—
Langlade CountyLanglade5108%160%3.631
Lincoln CountyLincoln394%159%3.671
Manitowoc CountyManitowoc494%157%4.541
Marathon CountyMarathon5103%172%3.681
Marinette CountyMarinette398%138%3.931
Marquette CountyMarquette5112%164%4.041
Menominee CountyMenominee5112%163%3.87—
Milwaukee CountyMilwaukee4118%123%5.111
Monroe CountyMonroe5116%203%3.74—
Oconto CountyOconto3105%153%4.151
Oneida CountyOneida387%155%3.87—
Outagamie CountyOutagamie493%182%4.111
Ozaukee CountyOzaukee5108%137%4.781
Pepin CountyPepin5122%146%3.461
Pierce CountyPierce5109%145%3.20—
Polk CountyPolk498%120%3.03—
Portage CountyPortage5101%184%3.761
Price CountyPrice492%149%3.72—
Racine CountyRacine4100%115%5.281
Richland CountyRichland5111%169%3.89—
Rock CountyRock295%120%4.981
Rusk CountyRusk5115%128%3.301
Sauk CountySauk5109%153%4.20—
Sawyer CountySawyer5109%144%3.44—
Shawano CountyShawano5104%167%3.96—
Sheboygan CountySheboygan498%145%4.541
St. Croix CountySt. Croix5104%149%3.07—
Taylor CountyTaylor5101%154%3.59—
Trempealeau CountyTrempealeau5140%168%3.52—
Vernon CountyVernon4109%204%3.84—
Vilas CountyVilas382%150%4.32—
Walworth CountyWalworth3100%127%5.271
Washburn CountyWashburn5108%135%3.21—
Washington CountyWashington5104%134%4.64—
Waukesha CountyWaukesha4115%127%5.091
Waupaca CountyWaupaca5106%175%3.861
Waushara CountyWaushara5106%187%3.871
Winnebago CountyWinnebago495%177%3.87—
Wood CountyWood4100%193%3.521

National Weather Service offices

The offices that issue forecasts and warnings for Wisconsin (National Weather Service, n.d.-a):

Questions

What can a strong El Niño winter do in Wisconsin?

In the 6 strong El Niño winters since 1965–66, 1 federal weather disaster declaration (recorded by FEMA) covered Wisconsin, including 34 of its 72 counties: Severe storms & flooding (1972–73).

Does El Niño bring more rain to Wisconsin?

In the seven strongest El Niño winters since 1950, 38 of Wisconsin's 72 counties with a full record got more December–February rain than their 1991–2020 normal in at least five of the seven, and 1 in two or fewer. The rest, 33, show no consistent pattern. Heavier winter rain came with the flood and storm disasters listed on this page, and a new National Flood Insurance Program policy usually takes 30 days to start.

What did the 1997–98 El Niño do in Wisconsin?

44 of 72 counties got more December–February rain than normal; the median county got 103% of normal.

How did the 2015–16 El Niño compare?

72 of 72 counties got more rain than normal, and the median county got 150% of normal, against 103% in 1997–98. A strong El Niño does not tell you which winter you will get, so prepare for the wet one: a new flood insurance policy usually takes 30 days to start.

Which National Weather Service offices cover Wisconsin?

NWS Milwaukee/Sullivan, WI, NWS La Crosse, WI, NWS Twin Cities, MN, NWS Duluth, MN, NWS Green Bay, WI. Enter a ZIP code above to find the one for your address.

How this page was made

Rain is NOAA’s monthly county series (Vose et al., 2014a, 2014b): December–February totals in the seven winters when NOAA’s relative Niño index was 1.5 °C or more (Climate Prediction Center, 2026a), against the 1991–2020 mean. Disasters are FEMA’s county designations for weather incidents beginning November to April, counted from 1965–66 (Federal Emergency Management Agency, 2026). Names are the Census Bureau’s (U.S. Census Bureau, 2020); offices are the National Weather Service’s county zones (National Weather Service, n.d.-a). Seven winters is a small sample, and the one ahead is forecast to be stronger than any of them (Climate Prediction Center, 2026b). Retrieved September 24, 2026.

References

  1. Climate Prediction Center. (2026a). Relative Oceanic Niño Index (RONI) [Dataset]. National Oceanic and Atmospheric Administration. https://www.cpc.ncep.noaa.gov/data/indices/RONI.ascii.txt
  2. Climate Prediction Center. (2026b, September 10). El Niño/Southern Oscillation (ENSO) diagnostic discussion. National Oceanic and Atmospheric Administration. https://www.cpc.ncep.noaa.gov/products/analysis_monitoring/enso_advisory/ensodisc.shtml
  3. Federal Emergency Management Agency. (n.d.). Flood after fire: The increased risk. Ready.gov. Retrieved https://www.ready.gov/sites/default/files/Flood_After_Fire_Fact_Sheet.pdf
  4. Federal Emergency Management Agency. (2026). OpenFEMA dataset: Disaster Declarations Summaries - v2 [Dataset]. https://www.fema.gov/openfema-data-page/disaster-declarations-summaries-v2
  5. FloodSmart. (n.d.). Buy a policy. Federal Emergency Management Agency. Retrieved September 24, 2026, from https://www.floodsmart.gov/get-insured/buy-a-policy
  6. National Climatic Data Center. (1998). Service Assessment and Report: The winter of 1997–1998 severe storms (Technical Report 98-02). NOAA National Climatic Data Center. https://www.ncei.noaa.gov/monitoring-content/billions/reports/19971201-19980228-severe-storm/tr9802.pdf
  7. National Weather Service. (n.d.-a). API web service. National Oceanic and Atmospheric Administration. Retrieved September 24, 2026, from https://www.weather.gov/documentation/services-web-api
  8. National Weather Service. (n.d.-b). NOAA Weather Radio. National Oceanic and Atmospheric Administration. Retrieved September 24, 2026, from https://www.weather.gov/nwr/
  9. National Weather Service. (n.d.-c). Turn Around Don’t Drown. National Oceanic and Atmospheric Administration. Retrieved September 24, 2026, from https://www.weather.gov/safety/flood-turn-around-dont-drown
  10. National Weather Service. (n.d.-d). Wireless Emergency Alerts. National Oceanic and Atmospheric Administration. Retrieved September 24, 2026, from https://www.weather.gov/wrn/wea
  11. Ready.gov. (n.d.-a). Financial preparedness. U.S. Department of Homeland Security. Retrieved September 24, 2026, from https://www.ready.gov/financial-preparedness
  12. Ready.gov. (n.d.-b). Tornadoes. U.S. Department of Homeland Security. Retrieved September 24, 2026, from https://www.ready.gov/tornadoes
  13. Ready.gov. (n.d.-c). Wildfires. U.S. Department of Homeland Security. Retrieved September 24, 2026, from https://www.ready.gov/wildfires
  14. Ready.gov. (n.d.-d). Winter weather. U.S. Department of Homeland Security. Retrieved September 24, 2026, from https://www.ready.gov/winter-weather
  15. U.S. Census Bureau. (2020). 2020 FIPS codes for counties and county equivalent entities [Dataset]. https://www2.census.gov/geo/docs/reference/codes2020/national_county2020.txt
  16. U.S. Census Bureau. (2024). 2024 Gazetteer files: ZIP Code Tabulation Areas [Dataset]. https://www.census.gov/geographies/reference-files/time-series/geo/gazetteer-files.html
  17. Vose, R. S., Applequist, S., Squires, M., Durre, I., Menne, M. J., Williams, C. N., Fenimore, C., Gleason, K., & Arndt, D. (2014a). Improved Historical Temperature and Precipitation Time Series for U.S. Climate Divisions. Journal of Applied Meteorology and Climatology, 53(5), 1232–1251. https://doi.org/10.1175/jamc-d-13-0248.1
  18. Vose, R. S., Applequist, S., Squires, M., Durre, I., Menne, M. J., Williams, C. N., Fenimore, C., Gleason, K., & Arndt, D. (2014b). NOAA Monthly U.S. Climate Divisional Database (NClimDiv) [Dataset]. NOAA National Centers for Environmental Information. https://doi.org/10.7289/V5M32STR
  19. Ward, A. (2026, September 16). Extreme meteorology (El Niño) with Dr. Marshall Shepherd [Audio podcast episode]. In Ologies with Alie Ward. https://www.alieward.com/ologies/extrememeteorology

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