St. Clair County, Michigan

St. Clair County, Michigan has a moderate overall risk from natural hazards in FEMA's National Risk Index. Its risk score is higher than 82% of US counties. It ranks 11th of 83 counties in Michigan. The costliest hazards here are inland flooding, cold waves and tornadoes. FEMA estimates about $49 million a year in expected losses, or roughly $308 per resident. Since 1972 it has been included in 9 federal disaster or emergency declarations for natural events (6 major disasters). The most recent was in September 2005 (Hurricane Katrina Evacuation). About 1 in 50 homes here carry federal flood insurance (1,248 policies). Since 1978, federal flood insurance has paid about $5.2 million on 1,184 claims here.

FEMA National Risk Index December 2025; OpenFEMA declarations to Nov 6, 2026; NFIP records. Updated November 6, 2026.

Scores are percentiles: a score of 90 means higher risk than about 90% of US counties for that hazard. Hazards FEMA does not rate here are left out. Social vulnerability is relatively low and community resilience is very high in FEMA's measures.

The National Weather Service has logged 425 storm reports in St. Clair County since 1953, with 5 deaths and 104 injuries and about $49.5 million in reported damage. The strongest on record here was an F4 tornado on May 21, 1953.

Source: NOAA Storm Events Database, county-based reports through Jul 18, 2026. Tornado records start in 1950, hail and wind in 1955, and floods and other storm types in 1996, so older decades undercount. Damage is in dollars of the year it happened and is often an estimate. Winter storms, heat and hurricanes are logged by forecast zone, not county, so they are not counted here.

Since 1955, 0 hurricanes and 1 tropical storm have passed within 65 miles of the center of St. Clair County, 1 of them since 1950. The strongest was Tropical Storm Connie (1955), with top winds near 45 mph about 60 miles away.

Source: NOAA National Hurricane Center best-track records (HURDAT2), 1851 to 2025 for the Atlantic and 1949 to 2025 for the eastern Pacific. A storm counts if its track passed within 65 miles of the county's center while it was a tropical storm or hurricane. Strength is the storm's top sustained wind at that point, not the wind measured in the county. Older storms over the open sea were sometimes missed.

National Flood Insurance Program (NFIP) records only; private flood policies are not included. Home counts as of Aug 3, 2026. Since 2021 NFIP prices each home separately under Risk Rating 2.0, so your price depends on the building, not the county. Ask an agent for a quote.

Older homes and mobile homes usually suffer more damage in storms, floods and earthquakes, and can cost more to insure. If you are buying, ask about roof age, foundation bolting and any retrofits. Source: US Census Bureau, American Community Survey 2020 to 2024 5-year estimates; 72,799 housing units.

Sources: FEMA National Risk Index (December 2025), OpenFEMA Disaster Declarations Summaries, and NFIP policy and claims data. Hazard Compass is independent and not affiliated with FEMA. These figures describe the whole county, not a single property, and are not insurance or safety advice. Report a problem.