Waukesha County, WI
FEMA National Risk Index scores, disaster declarations & hazard data
Waukesha County has experienced 19 federally declared disasters since 1969, most recently Severe Storms, Tornadoes, And Flooding in 2026. Its overall natural hazard risk is rated Relatively Moderate — near the middle compared to other US counties.
Waukesha County's highest-rated hazards are cold wave, hail, and tornado, with its top risk rated "Relatively High" by FEMA's National Risk Index. Recorded storm events have increased 215% over the past five years compared to the prior five-year period. Community vulnerability is relatively low (2nd percentile nationally), indicating stronger recovery capacity than most US counties.
Past disasters & FEMA designations
A federal disaster declaration officially designates a county for FEMA disaster assistance. Waukesha County has been designated in 19 declarations since 1969, covering 6 disaster types including flood (7), severe storm (6), biological (2).
| Year | Type | Event name |
|---|---|---|
| 2026 | Flood | Severe Storms, Tornadoes, And Flooding |
| 2025 | Flood | Severe Storms, Straight-Line Winds, Flooding, And Mudslides |
| 2020 | Biological | Covid-19 Pandemic |
| 2020 | Biological | Covid-19 |
| 2008 | Severe Storm | Severe Storms, Tornadoes, And Flooding |
| 2008 | Snowstorm | Record Snow And Near Record Snow |
| 2005 | Hurricane | Hurricane Katrina Evacuation |
| 2004 | Severe Storm | Severe Storms And Flooding |
| 2001 | Snowstorm | Snow |
| 2000 | Severe Storm | Severe Storms, Tornadoes, And Flooding |
Showing the 10 most recent of 19 total declarations since 1969.
Source: FEMA OpenFEMA Disaster Declarations Summaries. A single disaster can produce more than one record per county. Data current through September 2026.
Risk by hazard type
| Hazard | Risk rating | Risk score | Recorded events | Deaths | Prop. damage |
|---|---|---|---|---|---|
| Wildfire | Very Low | 49.7 | 0 | 0 | — |
| Inland Flooding | Relatively Moderate | 89.8 | 16 | 0 | $99.1M |
| Coastal Flooding | Not Applicable | — | 0 | 0 | — |
| Earthquake | Very Low | 57.4 | — | — | — |
| Heat Wave | Relatively Moderate | 90.4 | 11 | 0 | — |
| Tornado | Relatively High | 95.7 | 8 | 0 | — |
| Hurricane | Very Low | 9.7 | 0 | 0 | — |
| Hail | Relatively High | 96.1 | 98 | 0 | — |
| Strong Wind | Relatively Moderate | 56.1 | 0 | 0 | — |
| Winter Weather | Relatively High | 86.5 | 0 | 0 | — |
| Ice Storm | Relatively Moderate | 81.7 | — | — | — |
| Cold Wave | Relatively High | 97.4 | — | — | — |
| Lightning | Relatively Moderate | 60.2 | 4 | 0 | $2.6M |
| Drought | Relatively Low | 31.6 | 0 | 0 | — |
| Landslide | Relatively Low | 62.5 | 0 | 0 | — |
| Avalanche | Not Applicable | — | — | — | — |
| Tsunami | Not Applicable | — | — | — | — |
| Volcanic Activity | Not Applicable | — | — | — | — |
Scores are 0–100 percentiles relative to all US counties — higher means more exposed, not that a disaster is likely this year. Event counts: NOAA Storm Events 2016–2026; earthquake counts from USGS ComCat (M3.0+, 1996–2026). See the methodology page for details.
Community vulnerability
Waukesha County ranks in the 2nd percentile (Very low) for community vulnerability — a measure of how hard disaster impacts tend to hit residents. Higher vulnerability means more displacement, worse health outcomes, and slower recovery after a disaster.
| SVI theme | Percentile | Vulnerability level |
|---|---|---|
| Overall | 2nd | Very low |
| Socioeconomic status | 2nd | Very low |
| Household characteristics | 5th | Very low |
| Racial & ethnic minority status | 39th | Low |
| Housing type & transportation | 9th | Very low |
Source: CDC/ATSDR Social Vulnerability Index 2022. Percentiles compare counties nationally — higher means more vulnerable relative to other counties. See CDC SVI for full methodology.
Future risk outlook
| Wildfire metric | National percentile | Level |
|---|---|---|
| Burn probability | 23rd | Relatively Low |
| Risk to homes | 22nd | Relatively Low |
| Buildings in direct exposure zone | 41.8% | — |
NOAA tracked 137 weather events in this county over 2016–2025: 33 in 2016–20 vs 104 in 2021–25 (+215% — frequency increasing).
Wildfire: USDA Forest Service Wildfire Risk to Communities (RDS-2020-0016-2) — modeled values, not annual forecasts. See wildfirerisk.org. Inland flood and heat projections pending data availability; coastal sea-level projections are available for select coastal counties below — see the data page.
Nearby counties
Frequently asked questions
What natural hazards pose the greatest risk in Waukesha County?
According to the FEMA National Risk Index, the highest-risk hazards in Waukesha County, Wisconsin are cold wave, hail, and tornado. The county's overall natural hazard risk is rated Relatively Moderate — near the middle compared to other US counties.
Has Waukesha County received federal disaster declarations?
Yes. Waukesha County has received 19 federal disaster declarations since 1969, including declarations in 2026. The most common disaster type on record is flood (7 declarations).
Has Waukesha County had any FEMA disaster declarations in 2024, 2025, or 2026?
Yes. Recent federal disaster declarations for Waukesha County include Severe Storms, Tornadoes, And Flooding (2026), Severe Storms, Straight-Line Winds, Flooding, And Mudslides (2025). See the declarations table above for the full history since 1969.
How does Waukesha County's natural hazard risk compare to nearby counties?
Among neighboring counties, Milwaukee County, WI has the highest overall natural hazard risk (Relatively High) and Washington County, WI has the lowest (Relatively Low). Waukesha County is rated Relatively Moderate overall.
How is Waukesha County's composite disaster risk index calculated?
Waukesha County's composite disaster risk index — officially FEMA's National Risk Index (NRI) — scores every US county on a 0–100 percentile scale across 18 natural hazard types, factoring in expected annual loss, social vulnerability, and community resilience. Waukesha County's composite score of 89 means its overall natural hazard risk is higher than 89% of US counties.