St. Charles County, Missouri

What hazards hit St. Charles County most?

The most frequent records are severe thunderstorm wind events: 368 since 1958. The rank column places the county among Missouri's counties by days with a record per 1,000 square miles of land over each hazard's complete period.

Source: NOAA NCEI Storm Events Database (county and forecast-zone records attributed to the county; a zone record shows its own totals on each county it covers). Days: dates with at least one record of the hazard in the county. Ranks: days with a record per 1,000 square miles of land (Census Bureau 2024 Gazetteer), since 1950 for tornadoes, 1955 for hail and thunderstorm wind, 1996 for the rest.

How many tornadoes has St. Charles County had?

NOAA records 43 tornadoes in St. Charles County from 1954 to 2025, the strongest rated EF3, with 1 death and 89 injuries recorded in the county. That is 10th of 114 Missouri counties and 234th of 3,080 U.S. counties by days with tornadoes per 1,000 square miles since 1950. A tornado that crossed a county line is counted in each county it touched, with the length of its path inside the county.

Counted as whole tornadoes rather than county records, the Storm Prediction Center's database holds 45 tornadoes whose track touched St. Charles County since 1950 (NOAA's county records number 43: they file a crossing tornado once per county segment, and the two databases differ on some tracks); along their whole tracks they killed 1 person.

Map of the strongest tornado tracks in Missouri.

Source: NOAA NCEI Storm Events Database, tornado records by county (path length in the county, maximum width); ratings as published: F scale before February 1, 2007, EF scale after. Whole-track figures: NOAA Storm Prediction Center tornado database (1950-2025). SPC severe weather database.

When was the last damaging storm in St. Charles County?

The most recent record with damage, injuries or deaths is the June 25, 2026 thunderstorm wind ($10,000 in damage in 2025 dollars).

Source: NOAA NCEI Storm Events Database; every record of 2025-2026 is listed, earlier ones when they caused deaths, injuries or $250,000 of damage (2025 dollars), and every tornado.

The deadliest and costliest records

A damage figure marked "step" is a record from before 1993: NOAA then filed damage by category, and the figure is the category as entered, in the dollars of that year, not an estimate of the loss.

Source: NOAA NCEI Storm Events Database: deaths and injuries direct and indirect; damage is property plus crops as estimated by the National Weather Service, converted to 2025 dollars.

Is it getting more frequent?

Records per decade for St. Charles County's most frequent hazards. Counts rose everywhere after 1996, when NOAA began recording every event type, so compare decades within a hazard's complete period only (the shaded cells come before it).

Source: NOAA NCEI Storm Events Database, records per calendar decade; zone records from the CZ_TYPE field (Z).

What time of year?

Records by month in St. Charles County. The two busiest months are in violet.

Source: NOAA NCEI Storm Events Database, records by the month they began.

Federal disaster declarations for St. Charles County

FEMA's register lists 28 declarations that include St. Charles County: 19 major disasters, 9 emergencies and 0 fire management assistance declarations. Most were for severe storm (11) and flood (9).

Source: FEMA OpenFEMA Disaster Declarations Summaries (v2), declarations through October 2, 2026; one declaration is counted once however many areas it names. OpenFEMA dataset page.

How many floods has St. Charles County had?

NOAA's Storm Events Database holds 62 flood or flash flood records for St. Charles County from 1996 to 2026, on 61 days, with 2 deaths. By flood insurance claims since 1978 (OpenFEMA, as of September 8, 2026), St. Charles County ranks 53rd of 2,942 U.S. counties. The 100 counties with the most claims

The National Flood Insurance Program has paid $156 million on 9,999 claims filed in St. Charles County; the most in one year was 2,393 in 1993. Claims count insured losses only: uninsured flood damage is not in this file.

Source: FEMA OpenFEMA NFIP Redacted Claims, as of September 8, 2026; claims by year of loss, payments in the dollars of the year paid. OpenFEMA dataset page.

FEMA's modeled risk for St. Charles County

FEMA's National Risk Index rates St. Charles County Relatively Moderate overall, with an expected annual loss of $215 million. These are FEMA's model estimates of future loss from 18 hazards, not a count of what happened; they can differ from the record above.

Source: FEMA National Risk Index, county table, December 2025 release. FEMA's National Risk Index map.

Counties that share a border with St. Charles County

1. St. Louis County 1,651
2. Madison County, IL 1,009
3. St. Charles County 995
4. Franklin County 882
5. Lincoln County 537
6. Warren County 413
7. Jersey County, IL 388
8. Calhoun County, IL 270

Source: U.S. Census Bureau county adjacency file; NOAA NCEI Storm Events Database, records since 1950. The Census Bureau's adjacency file.

Next

• Tornadoes in MissouriEvery Missouri tornado since 1950 and the counties with the most per square mile
• Severe thunderstorm wind in MissouriThe state's severe thunderstorm wind events, by county, year and month
• The Missouri recordEvery hazard in the state, its deadliest events and its federal declarations
• FEMA's risk rating for each hazard in St. Charles CountyThe hazard risk calculator: 18 hazards beside the county's record
• Download St. Charles County's FEMA declarations (CSV)28 rows: every declaration that named the county, for your own analysis