Ozaukee County, Wisconsin
County storm and disaster record · FIPS 55089 · population 91,247 · 233 sq mi
NOAA's Storm Events Database holds 670 records for Ozaukee County, Wisconsin from 1950 through June 30, 2026, on 565 days; the most frequent are winter storm records (215 records). 445 of them are forecast-zone records, which the National Weather Service files once per zone: a county covered by several zones receives each one, so a single storm can add several records on the same day. The deadliest day on its record was August 20, 2018: rip current records filed for Ozaukee County that day count 2 deaths across 2 records. FEMA has issued 13 declarations naming the county since 1965, 11 of them for natural hazards; the latest for a natural hazard was “Severe Storms, Tornadoes, Straight-Line Winds, Flooding, and Landslides” on October 18, 2018.
The record, 1950 to 2026
Storm records filed for the county each year (2026 to June 30, 2026). Before 1996 NOAA recorded only tornadoes (from 1950), thunderstorm wind and hail (from 1955).
- recorded, no damage figure
- under $100,000
- $100,000 or more
- $1 million or more
- $10 million or more, or a death
- $100 million or more, or 10 deaths
- a year's colour: its recorded damage or deaths
- a year with a death
- 1955: wind and hail recorded from 1955
- 1996: all 48 event types from 1996
- Storm records
- 670on 565 days, 1950 to June 30, 2026
- Deaths recorded
- 542 injuries
- Damage, 2025 dollars
- $94Mas filed (scale steps before 1993)
- Tornadoes
- 4strongest F4
- FEMA declarations
- 13latest 2020
Source: NOAA NCEI Storm Events Database, records through June 30, 2026 (file revision 20260918); damage converted to 2025 dollars with the BLS CPI-U. Search the record at NCEI. BLS consumer price index.
What hazards hit Ozaukee County most?
The most frequent records are winter storm records: 215 since 1996. 56% of its winter storm records since 1996 fell in January and February. 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.
| Hazard | Records | Days | First, last | Killed | Injured | Damage | Rank in state |
|---|---|---|---|---|---|---|---|
| Winter storms | 215 | 214 | 1996-2026 | 1 | 0 | $84K | 2 of 72 |
| Severe thunderstorm wind | 85 | 67 | 1960-2024 | 0 | 6 | $7.6M | 10 of 72 |
| Fog, smoke and funnel clouds | 83 | 77 | 1996-2013 | 1 | 0 | – | 1 of 72 |
| Hail | 71 | 45 | 1961-2024 | 0 | 0 | $9.4M | 6 of 72 |
| High wind and dust storms | 55 | 55 | 1997-2026 | 0 | 0 | $1.3M | 3 of 72 |
| Floods | 45 | 32 | 1996-2026 | 1 | 3 | $47M | 5 of 72 |
| Heat | 35 | 35 | 1998-2026 | 0 | 0 | – | 3 of 72 |
| Extreme cold | 34 | 34 | 1996-2026 | 0 | 0 | $3K | 2 of 72 |
| Lightning | 19 | 15 | 1997-2012 | 0 | 3 | $2.7M | 4 of 72 |
| Drought | 17 | 17 | 2002-2012 | 0 | 0 | $235K | 1 of 72 |
| Heavy rain | 5 | 5 | 2003-2021 | 0 | 0 | $44K | 11 of 72 |
| Tornadoes | 4 | 3 | 1964-2015 | 0 | 30 | $25M | 60 of 72 |
| Rip currents and high surf | 2 | 1 | 2018-2018 | 2 | 0 | – | 6 of 72 |
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 Ozaukee County had?
NOAA records 4 tornadoes in Ozaukee County from 1964 to 2015, the strongest rated F4, with 0 deaths and 30 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 5 tornadoes whose track touched Ozaukee County since 1950 (NOAA's county records number 4: they file a crossing tornado once per county segment, and the two databases differ on some tracks); along their whole tracks they killed 0 people.
| Date | Tornado | Rating | Path | Killed |
|---|---|---|---|---|
| 1964-08-22 15:50, as SPC files it | Saukville | F4 | 2.2 mi | 0 |
Map of the strongest tornado tracks in Wisconsin.
Every tornado record filed for Ozaukee County (4)
| Date | Place | Character | Killed | Injured | Damage |
|---|---|---|---|---|---|
| 2015-08-10 | Freistadt, Ozaukee County | EF0 0.18 mi x 50 yd | 0 | 0 | $1K |
| 1996-07-18 | Port Washington Airport, Ozaukee County | F0 0.8 mi x 75 yd | 0 | 0 | – |
| 1996-07-18 | Fredonia, Ozaukee County | F1 7.6 mi x 125 yd | 0 | 0 | $997K |
| 1964-08-22 | Ozaukee County | F4 2.2 mi x 50 yd | 0 | 30 | $2.5M step |
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, 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 Ozaukee County?
The most recent record with damage, injuries or deaths is the April 14, 2026 flash flood ($5,000 in damage in 2025 dollars).
| Date | Record | Character | Killed | Injured | Damage |
|---|---|---|---|---|---|
| 2026-06-30 | Excessive HeatOzaukee County · forecast zone Ozaukee | 0 | 0 | – | |
| 2026-06-29 | Excessive HeatOzaukee County · forecast zone Ozaukee | 0 | 0 | – | |
| 2026-04-14 | Flash FloodBayside, Ozaukee County | 0 | 0 | $5K | |
| 2026-03-16 | BlizzardOzaukee County · forecast zone Ozaukee | 0 | 0 | – | |
| 2026-03-13 | High WindOzaukee County · forecast zone Ozaukee | 56 kt wind | 0 | 0 | $25K |
| 2026-02-28 | Winter WeatherOzaukee County · forecast zone Ozaukee | 0 | 0 | – | |
| 2026-01-23 | Extreme Cold/Wind ChillOzaukee County · forecast zone Ozaukee | 0 | 0 | – | |
| 2026-01-18 | Winter WeatherOzaukee County · forecast zone Ozaukee | 0 | 0 | – | |
| 2026-01-14 | Winter WeatherOzaukee County · forecast zone Ozaukee | 0 | 0 | – | |
| 2026-01-10 | Winter WeatherOzaukee County · forecast zone Ozaukee | 0 | 0 | – | |
| 2025-12-28 | Winter WeatherOzaukee County · forecast zone Ozaukee | 0 | 0 | – | |
| 2025-12-14 | Winter WeatherOzaukee County · forecast zone Ozaukee | 0 | 0 | – |
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
| Date | Record | Character | Killed | Injured | Damage |
|---|---|---|---|---|---|
| 2020-05-17 | FloodLake Church, Ozaukee County Numerous flooding reports all over the county with some road closures. Numerous basements flooded in Port Washington. A retaining wall collapsed onto an elderly woman in Port Washington, killing her. Two drivers rescued driving into deep water underneath a railroad bridge on Spring St. and Sunset Rd. in Port ... | 1 | 0 | $34K | |
| 2019-11-06 | Winter WeatherOzaukee County · forecast zone Ozaukee Snow accumulation of 4 to 5 inches. One indirect death from a vehicle accident on I-43 near Saukville around 8 AM. | 1 | 0 | – | |
| 2018-08-20 | Rip CurrentOzaukee County · forecast zone Ozaukee Ozaukee County Emergency Manager first alerted WFO MKX about a missing swimmer at Harrington Beach State Park along the Lake Michigan shore. A group of 5 people went swimming in dangerous swimming conditions when strong onshore winds were creating high waves and an increased risk of sub-surface currents. Of the five ... | 1 | 0 | – | |
| 2018-08-20 | Rip CurrentOzaukee County · forecast zone Ozaukee Ozaukee County Emergency Manager first alerted WFO MKX about a missing swimmer at Harrington Beach State Park along the Lake Michigan shore. A group of 5 people went swimming in dangerous swimming conditions when strong onshore winds were creating high waves and an increased risk of sub-surface currents. Of the five ... | 1 | 0 | – | |
| 2002-10-11 | Dense FogOzaukee County · forecast zone Ozaukee Shallow dense fog developed over parts of Sheboygan and Ozaukee counties during the overnight hours, and persisted to about 0830CST. The dense fog, reducing visibilities to zero to 1/4 mile, was a factor in three closely-spaced, but separate multi-vehicle accidents in Sheboygan County (total of 50 vehicles), and one ... | 1 | 0 | – | |
| 1964-08-22 | TornadoOzaukee County | F4 2.2 mi x 50 yd | 0 | 30 | $2.5M step |
| 1998-05-31 | Thunderstorm WindCountywide, Ozaukee County During the early morning hours of Sunday, May 31st, southcentral and southeast Wisconsin experienced an unprecedented, widespread downburst wind event known as a "derecho." Incredibly powerful, hurricane-force straight-line winds, with peak gusts of 100 to 128 mph tore through 12 counties in this part of the state, ... | 0 | 4 | $6.8M | |
| 2001-04-05 | LightningMequon, Ozaukee County Lightning struck a home, resulting in major structural damage to the chimney and roof, but there was no fire. Three landscape workers were injured when the lightning bolt split from the chimney and struck them while they were loading their truck. | 0 | 3 | $33K |
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.
| Date | Record | Character | Killed | Injured | Damage |
|---|---|---|---|---|---|
| 1996-06-18 | FloodOzaukee County · forecast zone Ozaukee | 0 | 0 | $13M | |
| 2004-06-01 | FloodOzaukee County · forecast zone Ozaukee | 0 | 0 | $12M | |
| 1996-06-18 | Flash FloodPort Washington, Ozaukee County | 0 | 0 | $10.0M | |
| 2006-04-13 | HailSaukville, Ozaukee County | 1.75 in hail | 0 | 0 | $9.3M |
| 1998-05-31 | Thunderstorm WindCountywide, Ozaukee County | 0 | 4 | $6.8M | |
| 1997-06-21 | Flash FloodMequon, Ozaukee County | 0 | 0 | $6.6M | |
| 1996-06-18 | Flash FloodBelgium, Ozaukee County | 0 | 0 | $1.9M | |
| 2010-06-23 | LightningMequon, Ozaukee County | 0 | 0 | $1.4M |
Before 1993 NOAA filed damage by category, not amount, so the list above starts in 1993. The highest category filed here before then (entered as $2.5M, in the dollars of the day) holds: August 22, 1964 (tornado, Ozaukee County).
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 Ozaukee 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).
| Hazard | 1950s | 1960s | 1970s | 1980s | 1990s | 2000s | 2010s | 2020-26 |
|---|---|---|---|---|---|---|---|---|
| Winter storms | – | – | – | – | 11 | 58 | 88 | 58 |
| Severe thunderstorm wind | 0 | 2 | 4 | 14 | 11 | 28 | 14 | 12 |
| Fog, smoke and funnel clouds | – | – | – | – | 4 | 65 | 14 | 0 |
| Hail | 0 | 2 | 5 | 4 | 6 | 25 | 15 | 14 |
| High wind and dust storms | – | – | – | – | 4 | 24 | 23 | 4 |
| Floods | – | – | – | – | 9 | 8 | 16 | 12 |
Source: NOAA NCEI Storm Events Database, records per calendar decade; zone records from the CZ_TYPE field (Z).
What time of year?
56% of its winter storm records since 1996 fell in January and February. The two busiest months are in violet.
The values, month by month
Jan 91 · Feb 75 · Mar 53 · Apr 50 · May 49 · Jun 60 · Jul 74 · Aug 58 · Sep 32 · Oct 23 · Nov 34 · Dec 71 (records).
Source: NOAA NCEI Storm Events Database, records by the month they began.
Federal disaster declarations for Ozaukee County
FEMA's register lists 13 declarations that include Ozaukee County: 10 major disasters, 3 emergencies and 0 fire management assistance declarations. Most were for flood (4) and severe storm (4).
| Declared | Number | Type | Title |
|---|---|---|---|
| 2020-04-04 | DR-4520 | Biological | Covid-19 Pandemic |
| 2020-03-13 | EM-3454 | Biological | Covid-19 |
| 2018-10-18 | DR-4402 | Flood | Severe Storms, Tornadoes, Straight-Line Winds, Flooding, and Landslides |
| 2008-06-14 | DR-1768 | Severe Storm | Severe Storms, Tornadoes, and Flooding |
| 2005-09-13 | EM-3249 | Hurricane | Hurricane Katrina Evacuation |
| 2004-06-18 | DR-1526 | Severe Storm | Severe Storms and Flooding |
| 2001-01-24 | EM-3163 | Snowstorm | Snow |
| 1997-07-07 | DR-1180 | Severe Storm | Severe Storms and Flooding |
| 1991-08-06 | DR-912 | Severe Storm | Severe Storms & Hail |
| 1986-10-07 | DR-775 | Flood | Severe Storms & Flooding |
| 1976-03-23 | DR-496 | Flood | Severe Storms, Icing, Wind & Flooding |
| 1973-04-27 | DR-376 | Flood | Severe Storms & Flooding |
| 1965-04-21 | DR-192 | Tornado | Tornadoes, Severe Storms & Flooding |
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 Ozaukee County had?
NOAA's Storm Events Database holds 45 flood or flash flood records for Ozaukee County from 1996 to 2026, on 32 days, with 1 death. By flood insurance claims since 1978 (OpenFEMA, as of September 8, 2026), Ozaukee County ranks 666th of 2,942 U.S. counties.
The National Flood Insurance Program has paid $3.9 million on 352 claims filed in Ozaukee County; the most in one year was 97 in 2008. Claims count insured losses only: uninsured flood damage is not in this file.
The values, year by year
1979: 5 · 1980: 2 · 1981: 3 · 1982: 3 · 1983: 1 · 1985: 1 · 1986: 25 · 1989: 10 · 1993: 5 · 1995: 1 · 1996: 22 · 1997: 38 · 1999: 5 · 2000: 4 · 2001: 3 · 2002: 1 · 2004: 42 · 2007: 3 · 2008: 97 · 2009: 2 · 2010: 2 · 2011: 1 · 2013: 7 · 2014: 3 · 2016: 1 · 2017: 1 · 2018: 8 · 2019: 26 · 2020: 2 · 2021: 1 · 2024: 1 · 2025: 22 · 2026: 4; the other years: 0.
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 Ozaukee County
FEMA's National Risk Index rates Ozaukee County Relatively Low overall, with an expected annual loss of $33.1 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.
| Hazard | Risk rating | Expected annual loss | Modeled frequency |
|---|---|---|---|
| Cold Wave | Relatively Moderate | $8.9M | 5.3 a year (modeled) |
| Hail | Relatively Low | $1.2M | 2.2 a year (modeled) |
| Tornado | Relatively Low | $3.5M | once in about 3 years (modeled) |
| Riverine Flooding | Relatively Low | $17M | 1 a year (modeled) |
| Heat Wave | Relatively Low | $994K | 2.2 modeled event-days a year |
| Winter Weather | Relatively Low | $107K | 16 a year (modeled) |
| Lightning | Relatively Low | $344K | 32 a year (modeled) |
| Strong Wind | Relatively Low | $608K | 2.4 a year (modeled) |
Source: FEMA National Risk Index, county table, December 2025 release. FEMA's National Risk Index map.
Counties that share a border with Ozaukee County
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
- Winter storms in WisconsinThe state's winter storm records, 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 Ozaukee CountyThe hazard risk calculator: 18 hazards beside the county's record
- Download Ozaukee County's FEMA declarations (CSV)13 rows: every declaration that named the county, for your own analysis