St. Charles County, MO

FEMA National Risk Index scores, disaster declarations & hazard data

Population: 405,183 · Cities: O'Fallon , St. Charles , St. Peters , Wentzville , Lake St. Louis , Dardenne Prairie

Relatively Moderate Riskier than 93% of US counties
Very Low Relatively Low Relatively Moderate Relatively High Very High

St. Charles County has experienced 28 federally declared disasters since 1965, most recently Severe Storms And Flooding in 2022. Its overall natural hazard risk is rated Relatively Moderate — near the middle compared to other US counties.

St. Charles County's highest-rated hazards are strong wind, hail, and tornado, with its top risk rated "Very High" by FEMA's National Risk Index. Recorded storm events have increased 60% over the past five years compared to the prior five-year period. Community vulnerability is relatively low (3rd percentile nationally), indicating stronger recovery capacity than most US counties.

Past disasters & FEMA designations

A federal disaster declaration officially designates a county for FEMA disaster assistance. St. Charles County has been designated in 28 declarations since 1965, covering 7 disaster types including severe storm (11), flood (9), severe ice storm (3).

2002–2026
Year Type Event name
2022 Flood Severe Storms And Flooding
2020 Biological Covid-19 Pandemic
2020 Biological Covid-19
2019 Severe Storm Severe Storms, Tornadoes, And Flooding
2016 Flood Severe Storms, Tornadoes, Straight-Line Winds, And Flooding
2016 Flood Severe Storms, Tornadoes, Straight-Line Winds, And Flooding
2013 Severe Storm Severe Storms, Straight-Line Winds, Tornadoes, And Flooding
2011 Severe Storm Severe Winter Storm
2011 Flood Flooding
2009 Severe Ice Storm Severe Winter Storm

Showing the 10 most recent of 28 total declarations since 1965.

Source: FEMA OpenFEMA Disaster Declarations Summaries. A single disaster can produce more than one record per county. Data current through September 2026.

Risk by hazard type

Hazard Risk rating Risk score Recorded events Deaths Prop. damage
Wildfire Very Low 58.8 0 0
Inland Flooding Relatively High 94.2 11 2 $11.2M
Coastal Flooding Not Applicable 0 0
Earthquake Relatively Moderate 94.6
Heat Wave Relatively Moderate 95.6 14 0
Tornado Relatively High 96.4 9 1 $3.6M
Hurricane Very Low 22.8 0 0
Hail Relatively High 97.6 70 0 $24.0M
Strong Wind Very High 98.1 0 0
Winter Weather Relatively High 89 0 0
Ice Storm Relatively Moderate 71.6
Cold Wave Relatively High 92.7
Lightning Relatively High 89.7 0 0
Drought Relatively Low 32.3 0 0
Landslide Relatively Moderate 92.8 0 0
Avalanche Not Applicable
Tsunami Not Applicable
Volcanic Activity Not Applicable

Scores are 0–100 percentiles relative to all US counties — higher means more exposed, not that a disaster is likely this year. Event counts: NOAA Storm Events 2016–2026; earthquake counts from USGS ComCat (M3.0+, 1996–2026). See the methodology page for details.

Community vulnerability

St. Charles County ranks in the 3rd percentile (Very low) for community vulnerability — a measure of how hard disaster impacts tend to hit residents. Higher vulnerability means more displacement, worse health outcomes, and slower recovery after a disaster.

SVI theme Percentile Vulnerability level
Overall 3rd Very low
Socioeconomic status 2nd Very low
Household characteristics 8th Very low
Racial & ethnic minority status 43rd Low
Housing type & transportation 12th Very low

Source: CDC/ATSDR Social Vulnerability Index 2022. Percentiles compare counties nationally — higher means more vulnerable relative to other counties. See CDC SVI for full methodology.

Future risk outlook

Wildfire metric National percentile Level
Burn probability 36th Relatively Low
Risk to homes 34th Relatively Low
Buildings in direct exposure zone 18.5%

NOAA tracked 104 weather events in this county over 2016–2025: 40 in 2016–20 vs 64 in 2021–25 (+60% — frequency increasing).

Wildfire: USDA Forest Service Wildfire Risk to Communities (RDS-2020-0016-2) — modeled values, not annual forecasts. See wildfirerisk.org. Inland flood and heat projections pending data availability; coastal sea-level projections are available for select coastal counties below — see the data page.

Nearby counties

Compare St. Charles County with other counties → All Missouri counties →

Frequently asked questions

What natural hazards pose the greatest risk in St. Charles County?

According to the FEMA National Risk Index, the highest-risk hazards in St. Charles County, Missouri are strong wind, hail, and tornado. The county's overall natural hazard risk is rated Relatively Moderate — near the middle compared to other US counties.

Has St. Charles County received federal disaster declarations?

Yes. St. Charles County has received 28 federal disaster declarations since 1965, including declarations in 2022. The most common disaster type on record is severe storm (11 declarations).

Has St. Charles County had any FEMA disaster declarations in 2024, 2025, or 2026?

No federal disaster declarations have been recorded for St. Charles County since the start of 2024. Its most recent declaration on record is Severe Storms And Flooding in 2022.

How does St. Charles County's natural hazard risk compare to nearby counties?

Among neighboring counties, St. Louis County, MO has the highest overall natural hazard risk (Relatively High) and Calhoun County, IL has the lowest (Very Low). St. Charles County is rated Relatively Moderate overall.

How is St. Charles County's composite disaster risk index calculated?

St. Charles County's composite disaster risk index — officially FEMA's National Risk Index (NRI) — scores every US county on a 0–100 percentile scale across 18 natural hazard types, factoring in expected annual loss, social vulnerability, and community resilience. St. Charles County's composite score of 93 means its overall natural hazard risk is higher than 93% of US counties.

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