St. Clair County, Missouri Natural Disaster Risk
FEMA National Risk Index assessment · MO
Very LowComposite Risk Score
National percentile: 26th
St. Clair County faces very low composite natural disaster risk (NRI Risk Index score 25.6, 26th national percentile), driven primarily by drought and ice storm exposure. Expected annual loss across all 18 hazard types is $6M.
Source: FEMA National Risk Index v1.20 · Updated December 2025
Risk Overview
FEMA's National Risk Index rates St. Clair County at very low composite risk, with a National Risk Index score of 25.6 out of 100 — placing it in the 26th national percentile and among the lowest-risk counties in the country. The score blends Expected Annual Loss, Social Vulnerability, and Community Resilience across all 18 FEMA hazard types.
Most of St. Clair County's expected losses come from drought (extended dry periods that stress water supplies and agriculture) at Medium risk — $699K in expected annual loss and about 12.82 events per year; ice storm (freezing rain that coats surfaces in heavy, damaging ice) at Medium risk — $147K in expected annual loss and about 0.57 events per year; and winter weather (heavy snow, blizzards, and hazardous winter conditions) at Medium risk — $80K in expected annual loss and about 11.21 events per year. Across all hazards, FEMA estimates $6M in expected annual loss for a population of 9K.
Beyond physical exposure, St. Clair County has a very high social vulnerability rating (how susceptible the population is to harm) and a low community resilience rating (its capacity to prepare for and recover from disasters). That combination — a more vulnerable population with limited resilience — can amplify the human cost of any given event.
The federal record bears this out: St. Clair County has received 24 federal disaster declarations since 1973, including 11 for severe storm events and 5 for severe ice storm events. The most recent was Severe Storms, Straight-Line Winds, Tornadoes, and Flooding (severe storm), declared in September 2023.
Among 115 Missouri counties, St. Clair County ranks #93 for overall natural disaster risk.
Top Hazards
All 18 Hazard Risks
| Drought | Medium | 12.82 / yr | $699K |
| Ice Storm | Medium | 0.57 / yr | $147K |
| Winter Weather | Medium | 11.21 / yr | $80K |
| Heat Wave | Low | 15.00 / yr | $362K |
| Wildfire | Very Low | 0.00 / yr | $40K |
| Cold Wave | Low | 2.26 / yr | $621K |
| Hail | Low | 6.55 / yr | $146K |
| Earthquake | Very Low | 0.00 / yr | $120K |
| Strong Wind | Low | 4.83 / yr | $298K |
| Tornado | Low | 0.43 / yr | $510K |
| Riverine Flood | Low | 1.82 / yr | $3M |
| Lightning | Low | 53.40 / yr | $87K |
| Landslide | Very Low | 0.28 / yr | $268 |
| Hurricane | Very Low | 0.01 / yr | $4K |
| Avalanche | Very Low | 0.00 / yr | $0 |
| Coastal Flood | Very Low | 0.00 / yr | $0 |
| Tsunami | Very Low | 0.00 / yr | $0 |
| Volcanic Activity | Very Low | 0.00 / yr | $0 |
Disaster History
St. Clair County has received 24 federal disaster declarations since 1973, most recently Severe Storms, Straight-Line Winds, Tornadoes, and Flooding in September 2023. Most frequent causes: Severe Storm (11), Severe Ice Storm (5), Flood (4).
| Declared | Type | Disaster |
|---|---|---|
| September 2023 | Severe Storm | Severe Storms, Straight-Line Winds, Tornadoes, and Flooding |
| March 2020 | Biological | Covid-19 Pandemic |
| March 2020 | Biological | Covid-19 |
| July 2019 | Severe Storm | Severe Storms, Tornadoes, and Flooding |
| January 2016 | Flood | Severe Storms, Tornadoes, Straight-Line Winds, and Flooding |
| January 2016 | Flood | Severe Storms, Tornadoes, Straight-Line Winds, and Flooding |
| August 2015 | Severe Storm | Severe Storms, Tornadoes, Straight-Line Winds, and Flooding |
| March 2011 | Severe Storm | Severe Winter Storm and Snowstorm |
| February 2011 | Severe Storm | Severe Winter Storm |
| January 2009 | Severe Ice Storm | Severe Winter Storm |
Showing the 10 most recent of 24 declarations.
Source: FEMA Disaster Declarations Summaries (OpenFEMA).
Frequently Asked Questions
What is the overall natural disaster risk for St. Clair County?
St. Clair County has a composite FEMA National Risk Index score of 25.6 out of 100, placing it in the Very Low category and the 26th national percentile. This combines Expected Annual Loss, Social Vulnerability, and Community Resilience across 18 hazard types.
What are the top natural hazards in St. Clair County?
The three highest-rated hazards are Drought (Medium, $699K EAL), Ice Storm (Medium, $147K EAL), Winter Weather (Medium, $80K EAL). These account for most of the county's expected annual losses.
How does St. Clair County compare to other Missouri counties?
St. Clair County ranks #93 of 115 Missouri counties for overall natural disaster risk, with a very low rating.
How many federally declared disasters has St. Clair County had?
FEMA records 24 federal disaster declarations for St. Clair County since 1973, most often 11 for severe storm events and 5 for severe ice storm events. The most recent was Severe Storms, Straight-Line Winds, Tornadoes, and Flooding, declared in September 2023.
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. St. Clair County's $6M EAL is a statistical average, not a guarantee for any specific year or address.