Chittenden County, Vermont Natural Disaster Risk
FEMA National Risk Index assessment · VT
LowComposite Risk Score
National percentile: 64th
Chittenden County faces low composite natural disaster risk (NRI Risk Index score 63.9, 64th national percentile), driven primarily by winter weather and lightning exposure. Expected annual loss across all 18 hazard types is $40M.
Source: FEMA National Risk Index v1.20 · Updated December 2025
Risk Overview
Chittenden County carries a low composite natural disaster risk, with a National Risk Index score of 63.9 out of 100 — placing it in the 64th national percentile and below the national average for natural-disaster risk. 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 winter weather (heavy snow, blizzards, and hazardous winter conditions) at Medium risk — $465K in expected annual loss and about 16.93 events per year; lightning (electrical discharges from storms that ignite fires and cause casualties) at High risk — $1M in expected annual loss and about 23.00 events per year; and avalanche (fast-moving snow and debris sliding down steep mountain slopes) at Medium risk — $457K in expected annual loss and about 0.03 events per year. Across all hazards, FEMA estimates $40M in expected annual loss for a population of 168K.
Beyond physical exposure, Chittenden County has a very 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.
History supports the rating: Chittenden County has received 32 federal disaster declarations since 1973, including 14 for severe storm events and 10 for flood events. The most recent was Severe Storm, Flooding, Landslides, and Mudslides (severe storm), declared in August 2024.
Among 14 Vermont counties, Chittenden County ranks #1 for overall natural disaster risk.
Top Hazards
All 18 Hazard Risks
| Winter Weather | Medium | 16.93 / yr | $465K |
| Lightning | High | 23.00 / yr | $1M |
| Avalanche | Medium | 0.03 / yr | $457K |
| Ice Storm | Medium | 0.33 / yr | $601K |
| Earthquake | Low | 0.00 / yr | $2M |
| Landslide | Low | 0.81 / yr | $18K |
| Riverine Flood | Medium | 2.14 / yr | $29M |
| Heat Wave | Low | 2.07 / yr | $2M |
| Hurricane | Low | 0.03 / yr | $661K |
| Strong Wind | Medium | 0.78 / yr | $1M |
| Cold Wave | Low | 3.47 / yr | $2M |
| Tornado | Low | 0.03 / yr | $847K |
| Wildfire | Very Low | 0.00 / yr | $19K |
| Hail | Very Low | 1.12 / yr | $99K |
| Coastal Flood | Very Low | 0.00 / yr | $0 |
| Drought | Very Low | 0.00 / yr | $0 |
| Tsunami | Very Low | 0.00 / yr | $0 |
| Volcanic Activity | Very Low | 0.00 / yr | $0 |
Disaster History
Chittenden County has received 32 federal disaster declarations since 1973, most recently Severe Storm, Flooding, Landslides, and Mudslides in August 2024. Most frequent causes: Severe Storm (14), Flood (10), Hurricane (3).
| Declared | Type | Disaster |
|---|---|---|
| August 2024 | Severe Storm | Severe Storm, Flooding, Landslides, and Mudslides |
| August 2024 | Tropical Storm | Tropical Depression Debby |
| April 2024 | Severe Storm | Severe Winter Storm |
| July 2023 | Flood | Severe Storms, Flooding, Landslides, and Mudslides |
| July 2023 | Flood | Flooding |
| March 2023 | Severe Storm | Severe Storm and Flooding |
| August 2021 | Hurricane | Tropical Storm Henri |
| April 2020 | Biological | Covid-19 Pandemic |
| March 2020 | Biological | Covid-19 |
| January 2020 | Severe Storm | Severe Storm and Flooding |
Showing the 10 most recent of 32 declarations.
Source: FEMA Disaster Declarations Summaries (OpenFEMA).
Frequently Asked Questions
What is the overall natural disaster risk for Chittenden County?
Chittenden County has a composite FEMA National Risk Index score of 63.9 out of 100, placing it in the Low category and the 64th national percentile. This combines Expected Annual Loss, Social Vulnerability, and Community Resilience across 18 hazard types.
What are the top natural hazards in Chittenden County?
The three highest-rated hazards are Winter Weather (Medium, $465K EAL), Lightning (High, $1M EAL), Avalanche (Medium, $457K EAL). These account for most of the county's expected annual losses.
How does Chittenden County compare to other Vermont counties?
Chittenden County ranks #1 of 14 Vermont counties for overall natural disaster risk, with a low rating.
How many federally declared disasters has Chittenden County had?
FEMA records 32 federal disaster declarations for Chittenden County since 1973, most often 14 for severe storm events and 10 for flood events. The most recent was Severe Storm, Flooding, Landslides, and Mudslides, declared in August 2024.
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. Chittenden County's $40M EAL is a statistical average, not a guarantee for any specific year or address.