Photo: Tommyers89 · CC BY-SA 4.0FEMA expects less hazard damage per building in Twin Falls than almost anywhere in the U.S., mostly from river and rain flooding
On FEMA’s National Risk Index, Twin Falls gets an A+ for hazard risk: among the lowest expected damage per building of U.S. towns, #2 of 59 in Idaho. Most of that expected damage is river and rain flooding (77%), then earthquakes (13%). Flood insurance has paid 11 claims here since 1979.
Graded on FEMA’s expected yearly building damage per dollar of building value (NRI v1.20, December 2025), weighted by where residents live; flood claims are shown, not graded. How hazard risk is graded
What Twin Falls faces
Each hazard’s share of the building damage FEMA expects here, and how its rate compares with the rest of the country.
River and rain flooding
Earthquakes
Wildfire
Shares are of FEMA’s expected building damage, the measure the grade uses; ranks compare each hazard’s building-damage rate with all 85,154 U.S. census tracts. In FEMA’s terms, river and rain flooding is FEMA’s “Inland Flooding” (rivers and streams overflowing their banks, or rain overwhelming drainage). FEMA defines coastal flooding as high or rising tides and storm surge, so surge damage is counted there. Drought isn’t listed: FEMA counts its losses in crops only.
What’s behind Twin Falls’ grade
River and rain flooding is 77% of the building damage FEMA expects in Twin Falls, and Twin Falls’ rate of river and rain flooding damage is lower than 90% of U.S. census tracts. Next is earthquakes at 13% (higher than 66% of U.S. census tracts).
A+ #2 of 59 in Idaho; among the lowest expected damage per building of U.S. towns (21,298).
Twin Falls’ residents live in 12 census tracts; FEMA’s figures are combined by where they live.
The typical Idaho town has higher expected damage than 52% of U.S. towns; within the state, Twin Falls has less expected damage per building than 98% of Idaho towns.
In dollars, FEMA expects about $7.5M a year in losses across Twin Falls: $4.9M to buildings, the rest to people and crops.
Does Twin Falls flood? Sometimes: 11 flood claims since 1979
Every paid claim on a federal flood insurance policy in Twin Falls, from FEMA’s records: 0.5 per 1,000 homes, fewer than 89% of the 13,809 U.S. towns with a flood insurance record.
Twin Falls isn’t in FEMA’s Community Rating System, which cuts flood insurance up to 45% in towns that do extra flood-proofing.
Insurance rates: Twin Falls County.The storms Twin Falls remembers
None of the 1 disasters declared for Twin Falls County shows FEMA aid or repair money reaching Twin Falls itself in FEMA’s records, so these are its biggest flood-claim years.
- 19793 flood claims paidNo declaration for the county that year
- 20142 flood claims paidNo declaration for the county that year
- 19831 flood claims paidNo declaration for the county that year
Twin Falls County has had 1 natural disasters declared by the President since 1953, most often floods. Not counted: the 2005 Hurricane Katrina evacuee emergency, which covered counties that took in evacuees.
Old photos of Twin Falls after a storm or flood belong in the town’s history. Add one, or share what you remember below.
Add to the Twin Falls archive →Get ready for what Twin Falls faces
A short kit for the hazards that drive the building damage here, what to check before you buy, and where neighbors get alerts.
- Turn around at flooded roads: a foot of moving water can carry off a car.
- Flood insurance usually takes 30 days to start, so buy it before the forecast.
- Keep papers and medicines up high, in a grab-and-go bag.
- Drop, cover and hold on.
- Strap tall furniture and the water heater to the wall.
- Know how to shut off the gas.
- Clear dead leaves and brush within 5 feet of the house.
- Sign up for local alerts and know two ways out.
- Keep N95 masks for smoky days.
- Look up the address on FEMA’s flood map.
- Ask the seller or landlord whether it has ever flooded, and what flood insurance costs there.
- Get a flood insurance quote early: policies usually start 30 days after you buy.
Know where neighbors sign up for alerts? Add it to the Handbook so everyone has it.
Questions about natural hazards in Twin Falls
Is Twin Falls at risk for natural disasters?
On FEMA’s National Risk Index, Twin Falls has among the lowest expected damage per building of U.S. towns: A+ for hazard risk, #2 of 59 in Idaho. Most of the expected damage is river and rain flooding (77%) and earthquakes (13%). This is FEMA’s model of an average year for today’s buildings, not a forecast.
Does Twin Falls flood?
Flood insurance has paid 11 claims in Twin Falls since 1979, $22K in all, or 0.5 per 1,000 homes, fewer than 89% of U.S. towns with a flood insurance record.
Is Twin Falls in a flood zone?
Flood zones are drawn street by street, so the answer depends on the address: look it up on FEMA’s flood map. In Twin Falls County, 21% of homes in mapped flood zones carry federal flood insurance, and 0.2% of all homes do.
How much is flood insurance in Twin Falls?
FEMA’s Community Rating System list shows no discount for Twin Falls’ flood program. Premiums depend on the building; policies usually start 30 days after you buy, so get a quote early.
Is Twin Falls at risk from river and rain flooding?
It is the largest share of the building damage FEMA expects here (77%), and Twin Falls’ rate for it is lower than 90% of U.S. census tracts.
Storm stories
Memories, warnings and help from neighbors in Twin Falls.
Sources: FEMA National Risk Index v1.20 (December 2025), census-tract table, combined by where Twin Falls’ residents lived in the 2020 census; OpenFEMA: NFIP redacted claims, multiple-loss properties, community status book and residential penetration rates, housing assistance (owners and renters), public assistance funded projects, hazard mitigation properties and disaster declarations. Homes: Census ACS 2020–24. Preparedness tips: Ready.gov. FEMA’s model is an average of expected damage, not a forecast. How hazard risk is graded.