Lyman County, South Dakota

Lyman County, South Dakota has a very low overall risk from natural hazards in FEMA's National Risk Index. Its risk score is lower than 74% of US counties. It ranks 28th of 66 counties in South Dakota. The costliest hazards here are cold waves, inland flooding and hail. FEMA estimates about $5.9 million a year in expected losses, or roughly $1,596 per resident. Since 1976 it has been included in 14 federal disaster or emergency declarations for natural events (12 major disasters). The most recent was in September 2019 (severe storms and flooding). Only 2 homes here carry federal flood insurance. Since 1978, federal flood insurance has paid about $393,000 on 16 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 very high and community resilience is relatively low in FEMA's measures.

The National Weather Service has logged 623 storm reports in Lyman County since 1957, with 2 deaths and 8 injuries and about $5.4 million in reported damage. The strongest on record here was an F3 tornado on July 9, 1971.

Source: NOAA Storm Events Database, county-based reports through Jul 19, 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.

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; 1,553 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.