Milwaukee County, Wisconsin Natural Disaster Risk
FEMA National Risk Index assessment · WI
HighComposite Risk Score
National percentile: 98th
Milwaukee County faces high composite natural disaster risk (NRI Risk Index score 98.4, 98th national percentile), driven primarily by cold wave and heat wave exposure. Expected annual loss across all 18 hazard types is $342M.
Source: FEMA National Risk Index v1.20 · Updated December 2025
Risk Overview
Overall natural disaster risk in Milwaukee County is high, with a National Risk Index score of 98.4 out of 100 — placing it in the 98th national percentile and in the upper tier of natural-disaster risk nationally. The score blends Expected Annual Loss, Social Vulnerability, and Community Resilience across all 18 FEMA hazard types.
The county's risk is driven primarily by cold wave (prolonged spells of dangerously low temperatures) at Very High risk — $177M in expected annual loss and about 4.89 events per year; heat wave (prolonged periods of extreme heat that threaten health and infrastructure) at High risk — $25M in expected annual loss and about 3.11 events per year; and tornado (violently rotating columns of air capable of catastrophic local damage) at Very High risk — $32M in expected annual loss and about 0.40 events per year. Across all hazards, FEMA estimates $342M in expected annual loss for a population of 939K.
Beyond physical exposure, Milwaukee County has a high social vulnerability rating (how susceptible the population is to harm) and a very high community resilience rating (its capacity to prepare for and recover from disasters). Higher vulnerability is partly offset by strong community resilience and recovery capacity.
The federal record bears this out: Milwaukee County has received 22 federal disaster declarations since 1969, including 8 for flood events and 7 for severe storm events. The most recent was Severe Storms, Tornadoes, and Flooding (flood), declared in June 2026.
Among 72 Wisconsin counties, Milwaukee County ranks #1 for overall natural disaster risk.
Top Hazards
All 18 Hazard Risks
| Cold Wave | Very High | 4.89 / yr | $177M |
| Heat Wave | High | 3.11 / yr | $25M |
| Tornado | Very High | 0.40 / yr | $32M |
| Riverine Flood | High | 2.11 / yr | $101M |
| Winter Weather | Very High | 15.84 / yr | $819K |
| Strong Wind | High | 3.13 / yr | $3M |
| Hail | Medium | 2.71 / yr | $1M |
| Earthquake | Low | 0.00 / yr | $2M |
| Ice Storm | Medium | 0.47 / yr | $287K |
| Lightning | Medium | 33.72 / yr | $309K |
| Coastal Flood | Very Low | 0.01 / yr | $7K |
| Landslide | Very Low | 0.05 / yr | $290 |
| Wildfire | Very Low | 0.00 / yr | $12K |
| Hurricane | Very Low | 0.01 / yr | $5K |
| Drought | Very Low | 1.46 / yr | $1K |
| Avalanche | Very Low | 0.00 / yr | $0 |
| Tsunami | Very Low | 0.00 / yr | $0 |
| Volcanic Activity | Very Low | 0.00 / yr | $0 |
Disaster History
Milwaukee County has received 22 federal disaster declarations since 1969, most recently Severe Storms, Tornadoes, and Flooding in June 2026. Most frequent causes: Flood (8), Severe Storm (7), Snowstorm (4).
| Declared | Type | Disaster |
|---|---|---|
| June 2026 | Flood | Severe Storms, Tornadoes, and Flooding |
| September 2025 | Flood | Severe Storms, Straight-Line Winds, Flooding, and Mudslides |
| April 2020 | Biological | Covid-19 Pandemic |
| March 2020 | Biological | Covid-19 |
| March 2020 | Flood | Severe Winter Storm and Flooding |
| April 2011 | Snowstorm | Severe Winter Storm and Snowstorm |
| August 2010 | Severe Storm | Severe Storms, Tornadoes, and Flooding |
| June 2008 | Severe Storm | Severe Storms, Tornadoes, and Flooding |
| March 2008 | Snowstorm | Record Snow and Near Record Snow |
| September 2005 | Hurricane | Hurricane Katrina Evacuation |
Showing the 10 most recent of 22 declarations.
Source: FEMA Disaster Declarations Summaries (OpenFEMA).
Frequently Asked Questions
What is the overall natural disaster risk for Milwaukee County?
Milwaukee County has a composite FEMA National Risk Index score of 98.4 out of 100, placing it in the High category and the 98th national percentile. This combines Expected Annual Loss, Social Vulnerability, and Community Resilience across 18 hazard types.
What are the top natural hazards in Milwaukee County?
The three highest-rated hazards are Cold Wave (Very High, $177M EAL), Heat Wave (High, $25M EAL), Tornado (Very High, $32M EAL). These account for most of the county's expected annual losses.
How does Milwaukee County compare to other Wisconsin counties?
Milwaukee County ranks #1 of 72 Wisconsin counties for overall natural disaster risk, with a high rating.
How many federally declared disasters has Milwaukee County had?
FEMA records 22 federal disaster declarations for Milwaukee County since 1969, most often 8 for flood events and 7 for severe storm events. The most recent was Severe Storms, Tornadoes, and Flooding, declared in June 2026.
What does Expected Annual Loss (EAL) mean?
EAL is FEMA's estimate of average annual dollar losses from natural hazards, calculated from historical event data and exposure models. Milwaukee County's $342M EAL is a statistical average, not a guarantee for any specific year or address.