Natural Hazard Risk by Region

Hurricanes and Tropical Systems

The Gulf Coast and Atlantic Seaboard bear the brunt of US hurricane impacts. Florida leads all states in hurricane-related FEMA declarations given its geographic exposure on two coasts. Louisiana and Texas face frequent Gulf storm landfalls, often with rapid intensification over warm Gulf waters that leaves little preparation time.

The hurricane risk corridor extends north through the Carolinas and Virginia, where nor'easters and landfalling tropical systems can cause severe flooding and wind damage far inland. Inland flooding from rainfall, not wind, accounts for the majority of hurricane fatalities and much of the damage documented in NOAA storm records.

Explore hurricane-affected states: State disaster profiles show each state's full declaration history and storm event counts.

Tornadoes

The US experiences more tornadoes than any other country on Earth, averaging 1,000-1,200 confirmed tornadoes per year. Two primary high-risk corridors emerge from the NOAA data:

Browse tornado event data by state and county on the hazard types page.

Flooding

Flooding is the single most costly and widespread natural hazard in the United States by FEMA declaration count. Unlike geographically concentrated hazards like hurricanes, flooding can occur in every state and is responsible for more FEMA declarations than any other disaster type.

Key flood-prone regions based on NOAA event frequency and FEMA data:

• Appalachian Region: Kentucky, West Virginia, and Tennessee experience severe flash flooding in narrow mountain valleys with limited warning time. Some counties hold decades of repeated flood declarations.
• Mississippi River Basin: Missouri, Illinois, Iowa, and Louisiana face periodic major riverine floods. The 1993 Great Flood and 2019 Missouri-Mississippi flooding are among the costliest on record.
• Gulf Coast: Louisiana, Texas, and Florida face compound flood risk from storm surge, riverine flooding, and tidal flooding, often simultaneously during tropical events.
• Great Plains: Spring snowmelt and intense convective storms create recurring flash flood risk across Nebraska, Kansas, and Oklahoma.

Explore flood-prone counties using PlainHazard's county-level data.

Wildfires

Wildfire risk in the US is heavily concentrated in the West. California has received more FEMA Fire Management Assistance Grants than any other state, often accounting for 30-50% of all FMAGs issued nationally in active fire years. Oregon, Washington, Colorado, Montana, Idaho, Nevada, and Arizona round out the highest-risk states.

The interaction of drought, high temperatures, low humidity, wind, and accumulated fuel loads creates conditions for rapid fire spread. Development at the wildland-urban interface has dramatically increased the human and economic toll, NOAA damage records for western wildfires have grown substantially since 2000.

Notably, the Southeast also has a significant prescribed and uncontrolled fire problem, Florida and Georgia rank among the top FMAG recipients outside the Mountain West.

Winter Storms and Ice Events

While winter storms receive less media attention than hurricanes and tornadoes, NOAA data shows they generate significant fatality and damage totals, particularly across the Northern Plains, Great Lakes region, and New England. The most dangerous winter events in the NOAA database are ice storms, freezing rain events that coat roads, power lines, and trees with ice, causing extended power outages and transportation disruptions.

The February 2021 winter storm that struck Texas (Winter Storm Uri) demonstrated that historically mild-climate regions can face catastrophic winter weather impacts when infrastructure is not hardened for extreme cold, it generated one of the costliest NOAA-recorded winter events in history.

Using PlainHazard to Explore Regional Risk

PlainHazard provides several ways to explore geographic hazard patterns:

• State profiles - FEMA declarations, storm event counts, fatalities, and damage by state
• County profiles - FEMA declarations at the county level for 2,729 counties
• Hazard types - 55+ NOAA event types with geographic breakdowns
• Rankings - Most disaster-prone states, costliest states, deadliest states

Region-by-region NRI risk profile cheat sheet

The FEMA National Risk Index lets us compare relative regional exposure across the eight headline natural hazards. The table below summarizes the dominant hazards in each US Census region. Per-county profiles vary substantially within each region, so use this as a starting point and check your specific county's NRI page for the exact breakdown.

Hazard dominance by Census region

Worked example: composite risk versus per-hazard risk

Two counties can have similar composite NRI scores but very different per-hazard breakdowns. Consider this comparison:

A coastal Texas county with a $14M annual EAL might allocate roughly $9M to hurricane and storm-surge exposure plus $3M to riverine flood and $2M to all other hazards combined; a Pacific Northwest county with the same $14M annual EAL might split as $7M earthquake plus $4M wildfire plus $3M flood. The composite cost is the same, but mitigation strategies differ entirely, coastal hardening and elevation versus seismic retrofit and defensible space.

Worked example: cost versus loss

Hurricane-prone counties show roughly 60% of national hurricane EAL versus 40% concentrated outside the South region. Tornado-prone Midwest counties show roughly 55% of national tornado EAL versus 45% spread across other regions. The Pareto-style concentration repeats across hazard types; a small share of counties bears most modeled risk.

Cross-checking against historical declarations

Modeled NRI EAL is forward-looking. Pair it with historical FEMA declaration counts to validate that the modeled risk aligns with actual federal-aid history for the county. If NRI projects a high EAL but FEMA shows few historical declarations, the mismatch may indicate either rare-but-catastrophic exposure (the model is correct, history is sparse) or a model overestimate (the model is wrong, history is right). Either interpretation matters for insurance and mitigation planning.