Portage County, Wisconsin

What hazards hit Portage County most?

The most frequent records are severe thunderstorm wind events: 154 since 1967. 60% of its severe thunderstorm wind events since 1967 fell in June and July. The rank column places the county among Wisconsin's counties by days with a record per 1,000 square miles of land over each hazard's complete period.

Source: NOAA NCEI Storm Events Database (county and forecast-zone records attributed to the county; a zone record shows its own totals on each county it covers). Days: dates with at least one record of the hazard in the county. Ranks: days with a record per 1,000 square miles of land (Census Bureau 2024 Gazetteer), since 1950 for tornadoes, 1955 for hail and thunderstorm wind, 1996 for the rest.

How many tornadoes has Portage County had?

NOAA records 25 tornadoes in Portage County from 1951 to 2025, the strongest rated F4, with 2 deaths and 4 injuries recorded in the county. A tornado that crossed a county line is counted in each county it touched, with the length of its path inside the county.

Counted as whole tornadoes rather than county records, the Storm Prediction Center's database holds 25 tornadoes whose track touched Portage County since 1950 (NOAA's county records number 25, the same count); along their whole tracks they killed 8 people, 2 of them in Portage County.

Map of the strongest tornado tracks in Wisconsin.

Source: NOAA NCEI Storm Events Database, tornado records by county (path length in the county, maximum width); ratings as published: F scale before February 1, 2007, EF scale after. Whole-track figures: NOAA Storm Prediction Center tornado database (1950-2025). SPC severe weather database.

When was the last damaging storm in Portage County?

The most recent record with damage, injuries or deaths is the May 3, 2020 dust storm ($342,000 in damage in 2025 dollars).

Strong winds of 30 to 40 mph caused dust and dirt from a nearby farmers field to be lifted into the air, reducing visibilities to near zero across a small portion of Interstate 39 and Coundy D north of Plainfield. There was a multiple car accident of 30 to 35 cars on north and southbound lanes of Interstate 39 and the interstate was closed through the early evening hours. The cars were either severely damaged or totaled.
National Weather Service event narrative, NOAA Storm Events Database (search the full record, event 879867)

Source: NOAA NCEI Storm Events Database; every record of 2025-2026 is listed, earlier ones when they caused deaths, injuries or $250,000 of damage (2025 dollars), and every tornado.

The deadliest and costliest records

A damage figure marked "step" is a record from before 1993: NOAA then filed damage by category, and the figure is the category as entered, in the dollars of that year, not an estimate of the loss.

Source: NOAA NCEI Storm Events Database: deaths and injuries direct and indirect; damage is property plus crops as estimated by the National Weather Service, converted to 2025 dollars.

Is it getting more frequent?

Records per decade for Portage County's most frequent hazards. Counts rose everywhere after 1996, when NOAA began recording every event type, so compare decades within a hazard's complete period only (the shaded cells come before it).

Source: NOAA NCEI Storm Events Database, records per calendar decade; zone records from the CZ_TYPE field (Z).

What time of year?

60% of its severe thunderstorm wind events since 1967 fell in June and July. The two busiest months are in violet.

Source: NOAA NCEI Storm Events Database, records by the month they began.

Federal disaster declarations for Portage County

FEMA's register lists 12 declarations that include Portage County: 9 major disasters, 3 emergencies and 0 fire management assistance declarations. Most were for severe storm (4) and flood (3).

Source: FEMA OpenFEMA Disaster Declarations Summaries (v2), declarations through October 2, 2026; one declaration is counted once however many areas it names. OpenFEMA dataset page.

How many floods has Portage County had?

NOAA's Storm Events Database holds 16 flood or flash flood records for Portage County from 1996 to 2021, on 13 days, with 0 deaths. By flood insurance claims since 1978 (OpenFEMA, as of September 8, 2026), Portage County ranks 2061st of 2,942 U.S. counties.

The National Flood Insurance Program has paid $166,000 on 22 claims filed in Portage County; the most in one year was 8 in 2010. Claims count insured losses only: uninsured flood damage is not in this file.

Source: FEMA OpenFEMA NFIP Redacted Claims, as of September 8, 2026; claims by year of loss, payments in the dollars of the year paid. OpenFEMA dataset page.

FEMA's modeled risk for Portage County

FEMA's National Risk Index rates Portage County Relatively Low overall, with an expected annual loss of $35.9 million. These are FEMA's model estimates of future loss from 18 hazards, not a count of what happened; they can differ from the record above.

Source: FEMA National Risk Index, county table, December 2025 release. FEMA's National Risk Index map.

Counties that share a border with Portage County

1. Marathon County 882
2. Wood County 541
3. Waupaca County 533
4. Portage County 521
5. Adams County 477
6. Shawano County 462
7. Waushara County 433

Source: U.S. Census Bureau county adjacency file; NOAA NCEI Storm Events Database, records since 1950. The Census Bureau's adjacency file.

Next

• Tornadoes in WisconsinEvery Wisconsin tornado since 1950 and the counties with the most per square mile
• Severe thunderstorm wind in WisconsinThe state's severe thunderstorm wind events, by county, year and month
• The Wisconsin recordEvery hazard in the state, its deadliest events and its federal declarations
• FEMA's risk rating for each hazard in Portage CountyThe hazard risk calculator: 18 hazards beside the county's record
• Download Portage County's FEMA declarations (CSV)12 rows: every declaration that named the county, for your own analysis