Marathon County, Wisconsin Natural Disaster Risk
FEMA National Risk Index assessment · WI
MediumComposite Risk Score
National percentile: 87th
Marathon County faces medium composite natural disaster risk (NRI Risk Index score 87.2, 87th national percentile), driven primarily by cold wave and lightning exposure. Expected annual loss across all 18 hazard types is $75M.
Source: FEMA National Risk Index v1.20 · Updated December 2025
Risk Overview
Overall natural disaster risk in Marathon County is medium, with a National Risk Index score of 87.2 out of 100 — placing it in the 87th national percentile and near the national midpoint for natural-disaster risk. The score blends Expected Annual Loss, Social Vulnerability, and Community Resilience across all 18 FEMA hazard types.
Risk here concentrates in cold wave (prolonged spells of dangerously low temperatures) at High risk — $27M in expected annual loss and about 8.79 events per year; lightning (electrical discharges from storms that ignite fires and cause casualties) at High risk — $2M in expected annual loss and about 31.86 events per year; and hail (ice stones from severe thunderstorms that damage property and crops) at Medium risk — $2M in expected annual loss and about 2.21 events per year. Across all hazards, FEMA estimates $75M in expected annual loss for a population of 138K.
Beyond physical exposure, Marathon County has a low 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). A less vulnerable population paired with strong resilience helps the community absorb and recover from events.
The county's disaster history tells the same story: Marathon County has received 12 federal disaster declarations since 1965, including 4 for severe storm events and 2 for flood events. The most recent was Severe Storms, Tornadoes, and Flooding (flood), declared in June 2026.
Among 72 Wisconsin counties, Marathon County ranks #5 for overall natural disaster risk.
Top Hazards
All 18 Hazard Risks
| Cold Wave | High | 8.79 / yr | $27M |
| Lightning | High | 31.86 / yr | $2M |
| Hail | Medium | 2.21 / yr | $2M |
| Riverine Flood | Medium | 0.79 / yr | $36M |
| Tornado | Medium | 0.60 / yr | $6M |
| Winter Weather | Medium | 16.21 / yr | $155K |
| Heat Wave | Low | 1.37 / yr | $745K |
| Landslide | Very Low | 0.21 / yr | $3K |
| Ice Storm | Low | 0.19 / yr | $147K |
| Strong Wind | Medium | 2.12 / yr | $753K |
| Wildfire | Very Low | 0.00 / yr | $29K |
| Earthquake | Very Low | 0.00 / yr | $27K |
| Avalanche | Very Low | 0.00 / yr | $0 |
| Coastal Flood | Very Low | 0.00 / yr | $0 |
| Drought | Very Low | 0.00 / yr | $0 |
| Hurricane | Very Low | 0.00 / yr | $0 |
| Tsunami | Very Low | 0.00 / yr | $0 |
| Volcanic Activity | Very Low | 0.00 / yr | $0 |
Disaster History
Marathon County has received 12 federal disaster declarations since 1965, most recently Severe Storms, Tornadoes, and Flooding in June 2026. Most frequent causes: Severe Storm (4), Flood (2), Biological (2).
| Declared | Type | Disaster |
|---|---|---|
| June 2026 | Flood | Severe Storms, Tornadoes, and Flooding |
| April 2020 | Biological | Covid-19 Pandemic |
| March 2020 | Biological | Covid-19 |
| October 2010 | Severe Storm | Severe Storms and Flooding |
| September 2005 | Hurricane | Hurricane Katrina Evacuation |
| June 2004 | Severe Storm | Severe Storms and Flooding |
| September 2002 | Tornado | Severe Storms, Tornadoes and Flooding |
| July 2002 | Severe Storm | Severe Storms and Flooding |
| July 1993 | Severe Storm | Severe Storms, Tornadoes & Flooding |
| June 1976 | Drought | Drought |
Showing the 10 most recent of 12 declarations.
Source: FEMA Disaster Declarations Summaries (OpenFEMA).
Frequently Asked Questions
What is the overall natural disaster risk for Marathon County?
Marathon County has a composite FEMA National Risk Index score of 87.2 out of 100, placing it in the Medium category and the 87th national percentile. This combines Expected Annual Loss, Social Vulnerability, and Community Resilience across 18 hazard types.
What are the top natural hazards in Marathon County?
The three highest-rated hazards are Cold Wave (High, $27M EAL), Lightning (High, $2M EAL), Hail (Medium, $2M EAL). These account for most of the county's expected annual losses.
How does Marathon County compare to other Wisconsin counties?
Marathon County ranks #5 of 72 Wisconsin counties for overall natural disaster risk, with a medium rating.
How many federally declared disasters has Marathon County had?
FEMA records 12 federal disaster declarations for Marathon County since 1965, most often 4 for severe storm events and 2 for flood 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. Marathon County's $75M EAL is a statistical average, not a guarantee for any specific year or address.