Natural disaster risk in Waukesha County, Wisconsin

Wisconsin · population 406,817 · FIPS 55133

Overall: relatively moderate risk

Waukesha County has a composite risk score of 88.9 out of 100 — higher than 88% of US counties. It ranks 4 of 72 in Wisconsin (1 = highest risk). Its highest-rated hazards are cold wave, hail, tornado.

Drought now: No: no drought or dryness

No. On the U.S. Drought Monitor map valid 13 October 2026, no part of Waukesha County is in drought or abnormally dry (none of D0 to D4). That has been so for 4 weeks in a row.

Drought in Waukesha County: the last 52 weeks · droughtmonitor.unl.edu

The U.S. Drought Monitor is jointly produced by the National Drought Mitigation Center at the University of Nebraska-Lincoln, the United States Department of Agriculture, the National Oceanic and Atmospheric Administration and the National Aeronautics and Space Administration. Map courtesy of NDMC.

Risk, loss, vulnerability and resilience

MeasureRating and score
Overall risk
Expected annual loss, adjusted for social vulnerability and community resilience.
Relatively moderate 88.9
Expected annual loss
About $138.3 million a year, on average, across all 18 hazards.
Relatively moderate 93.6
Social vulnerability
Higher means people may find it harder to prepare and recover.
Very low 10.6
Community resilience
Higher means a stronger ability to prepare, adapt and recover.
Very high 97.4

Risk by hazard

FEMA's risk rating for each of 18 natural hazards in Waukesha County, highest first. "Not applicable" means the hazard is not modelled here.

HazardRisk rating and score
Cold wave Relatively high 97
Hail Relatively high 96
Tornado Relatively high 95
Winter weather Relatively high 86
Heat wave Relatively moderate 90
Inland (riverine) flooding Relatively moderate 89
Ice storm Relatively moderate 81
Lightning Relatively moderate 60
Strong wind Relatively moderate 56
Landslide Relatively low 62
Drought Relatively low 31
Earthquake Very low 57
Wildfire Very low 49
Hurricane Very low 9
Avalanche Not applicable
Coastal flooding Not applicable
Tsunami Not applicable
Volcanic activity Not applicable

FEMA disaster declarations for Waukesha County

Federal declarations that designated Waukesha County, since 1 Jan 2024 (the period this site keeps from OpenFEMA). Older declarations are in FEMA's own dataset.

Yes. Waukesha County has been named in 2 FEMA declarations since 1 Jan 2024. The latest is DR-4923-WI (Severe Storms, Tornadoes, and Flooding), declared 30 Jun 2026.

DeclarationKindIncidentDeclaredIndividual assistance here
DR-4923-WI Major disaster Severe Storms, Tornadoes, and Flooding 30 Jun 2026 Yes
DR-4892-WI Major disaster Severe Storms, Straight-Line Winds, Flooding, and Mudslides 11 Sep 2025 Yes

All FEMA declarations in Wisconsin, with estimated apply-by dates · Open FEMA deadlines

This product uses the Federal Emergency Management Agency's OpenFEMA API, but is not endorsed by FEMA. The Federal Government or FEMA cannot vouch for the data or analyses derived from these data after the data have been retrieved from the Agency's website(s). Dataset: Disaster Declarations Summaries - v2.

How to read these ratings

  • Ratings run in five steps: very low, relatively low, relatively moderate, relatively high and very high. They compare a county with every other US county; they are not a measure of danger on their own.
  • Scores run from 0 to 100 and are national percentiles. The bar shows the score: a score of 80 means a higher value than 80% of US counties.
  • Overall risk combines the expected annual loss with social vulnerability and community resilience.
  • Expected annual loss is the average yearly loss to buildings, people and agriculture the model expects from all 18 hazards.
  • Social vulnerability describes how hard it may be for people to prepare for and recover from a disaster. Higher is worse.
  • Community resilience describes a community's ability to prepare, adapt and recover. Higher is better.
  • "Not applicable" means FEMA does not model that hazard there (for example, hurricanes far inland).

About this data

Source: FEMA National Risk Index, version 1.20, released December 2025, published by the Federal Emergency Management Agency (US public domain). About the National Risk Index. The index is a model of relative risk built from historical hazard records, what is exposed and community factors. It is not a forecast, it does not describe any single property, and it is not insurance or financial advice. For decisions about a specific address, check FEMA's flood maps and your local emergency management office.

Questions

What is the natural disaster risk in Waukesha County, Wisconsin?

FEMA's National Risk Index rates the overall risk in Waukesha County as relatively moderate, with a score of 88.9 out of 100 (higher than 88% of US counties). That is a comparison with other US counties, not a forecast.

What are the biggest natural hazards in Waukesha County?

The hazards rated highest for Waukesha County are cold wave (relatively high), hail (relatively high), tornado (relatively high).

What is the flood risk in Waukesha County?

FEMA rates inland (river and rain) flooding risk in Waukesha County as relatively moderate. For a specific property, check the FEMA flood map and your local floodplain office.

Has Waukesha County had a FEMA disaster declaration?

Yes. Waukesha County has been named in 2 FEMA declarations since 1 Jan 2024. The latest is DR-4923-WI (Severe Storms, Tornadoes, and Flooding), declared 30 Jun 2026.

Is Waukesha County in a drought?

No. On the U.S. Drought Monitor map valid 13 October 2026, no part of Waukesha County is in drought or abnormally dry (none of D0 to D4). That has been so for 4 weeks in a row.

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