Hurricane Risk in the US: How FEMA Scores It and How to Prepare

Hurricanes are the most expensive natural disasters in American history. Katrina (2005), Harvey (2017), Ian (2022), and Helene (2024) each caused tens of billions of dollars in damage, and a single landfall can generate more insured loss than a decade of tornadoes. In FEMA’s National Risk Index, hurricane risk (hazard code HRCN) accounts for roughly $12.5 billion in expected annual loss nationally — and unlike most hazards, that loss is heavily concentrated in a narrow coastal band.

What counts as hurricane risk

A hurricane is a tropical cyclone with sustained winds of at least 74 mph, but the NRI’s hurricane hazard covers the whole destructive package a tropical system delivers: extreme wind, torrential rain, and — most lethal of all — storm surge, the dome of seawater a storm pushes ashore. Surge, not wind, causes most hurricane deaths and much of the catastrophic property loss near the coast. Inland, the biggest killer is freshwater flooding from rainfall, which is why hurricane damage routinely reaches hundreds of miles from landfall (the NRI books much of that rainfall flooding under its separate riverine-flood hazard).

Hurricane season runs June through November in the Atlantic, peaking from mid-August to mid-October. The Gulf Coast, Florida, and the Southeast Atlantic coast take most landfalls, but the Northeast is not exempt — Sandy (2012) remains one of the costliest US storms ever, and New England has been hit by major hurricanes before.

How the NRI measures it

For each county, FEMA combines three things: exposure (the value of buildings, people, and agriculture in the hurricane-prone area), annualized frequency (how often hurricane conditions historically affect the county, from National Hurricane Center track data), and historic loss ratio (the share of exposed value a typical event destroys). Multiplied together, they yield the county’s hurricane Expected Annual Loss, which is then scored 0–100 relative to every other county.

Note what this means: a huge metro that sees a hurricane once a decade can outscore a rural coastal county hit far more often, because there is simply more value in harm’s way. Frequency alone is not risk.

Where the risk concentrates

In the current dataset (NRI v1.20), 2,230 counties record measurable hurricane risk, but the top of the list is unambiguous. Harris County, Texas (Houston) leads the nation with a hurricane score of 100 and roughly $458 million in expected annual loss. Florida dominates the rest of the top tier: Miami-Dade (~$331M EAL), Palm Beach (~$287M), Lee County (~$300M — ground zero for Ian in 2022), and Broward (~$280M). Louisiana’s coastal parishes, coastal Texas, and the Carolinas fill out the highest ratings.

The pattern to notice: every one of these places pairs frequent tropical activity with enormous, still-growing coastal development. Hurricane risk is rising not mainly because storms are more frequent, but because more value sits in their path every year — and because warmer water lets storms intensify faster and carry more rain.

How to read your county’s score

If your county rates High or Very High for hurricanes, the practical questions are: Are you in a storm-surge evacuation zone (check your county emergency management office’s maps — these are different from FEMA flood maps)? Is your home built to modern wind code? Florida’s post-Andrew building codes measurably reduce losses. Do you carry flood insurance? Standard homeowners policies exclude flood damage, including hurricane storm surge — that requires a separate NFIP or private flood policy, with a typical 30-day waiting period.

A Medium rating in an inland county usually reflects rainfall and wind from decaying storms — think power outages and flooded creeks rather than surge.

What actually reduces the risk

• Know your evacuation zone before the season starts. Surge zones (A, B, C…) determine who must leave. Most people who die in surge were in a zone told to evacuate.
• Protect the openings. Once wind breaches a window or garage door, internal pressure can fail the roof. Rated shutters or plywood on windows and a braced garage door are the highest-value structural upgrades.
• Roof connections matter most. Hurricane straps/clips tying roof to walls are cheap during a re-roof and dramatically improve survival; the FORTIFIED standard is the benchmark and earns insurance discounts in many coastal states.
• Buy flood insurance even outside the mapped floodplain. A large share of hurricane flood claims come from properties outside high-risk flood zones.
• Prepare for the aftermath, not just the storm. Water, food, medication, cash, and fuel for 7+ days; grid restoration after a major landfall can take weeks. Never run a generator indoors or near openings — carbon-monoxide poisoning is a leading post-storm killer.

Sources

• National Hurricane Center — forecasts, surge maps, historical tracks
• FEMA NRI hurricane methodology
• Ready.gov hurricane preparedness
• NOAA billion-dollar disasters — historical hurricane loss records