Photo: Jyoni Shuler · CC BY-SA 4.0Less hazard damage per building is expected in Boise City than in 71% of U.S. towns, mostly from river and rain flooding
On FEMA’s National Risk Index, Boise City gets a B+ for hazard risk: lower expected damage per building than 71% of U.S. towns, #20 of 59 in Idaho. Most of that expected damage is river and rain flooding (66%), then wildfire (26%). Flood insurance has paid 13 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 Boise City 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
Wildfire
Earthquakes
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 Boise City’s grade
River and rain flooding is 66% of the building damage FEMA expects in Boise City, and Boise City’s rate of river and rain flooding damage is lower than 58% of U.S. census tracts. Wildfire adds 26%, at a rate in the top 4% of U.S. census tracts.
B+ #20 of 59 in Idaho; lower expected damage per building than 71% of U.S. towns (21,298).
Boise City’s residents live in 74 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, Boise City has less expected damage per building than 67% of Idaho towns.
Among the 400 U.S. cities of 100,000 or more, Boise City has lower expected damage per building than 82% (#73 of 400). Because it is so big, its total expected yearly loss, $56.2M, is the 218th largest of those 400.
Does Boise City flood? Sometimes: 13 flood claims since 1979
Every paid claim on a federal flood insurance policy in Boise City, from FEMA’s records: 0.1 per 1,000 homes, fewer than 99% of the 13,809 U.S. towns with a flood insurance record.
Boise City isn’t in FEMA’s Community Rating System, which cuts flood insurance up to 45% in towns that do extra flood-proofing.
Insurance rates: Ada County.The storms Boise City remembers
None of the 3 disasters declared for Ada County shows FEMA aid or repair money reaching Boise City itself in FEMA’s records, so these are its biggest flood-claim years.
- 20062 flood claims paidNo declaration for the county that year
- 20172 flood claims paidThe year of Flooding, declared for Ada County
- 19791 flood claims paidNo declaration for the county that year
Ada County has had 3 natural disasters declared by the President since 1953, most often floods, then severe storms. Not counted: the 2005 Hurricane Katrina evacuee emergency, which covered counties that took in evacuees.
Old photos of Boise City after a storm or flood belong in the town’s history. Add one, or share what you remember below.
Add to the Boise City archive →Boise City and its neighbors
Boise City is 2nd of the 4 graded towns here, from least expected damage per building to most. Tap a town to see its hazards.
| Town | Hazard risk | Mostly (buildings) | Flood claims |
|---|---|---|---|
| Meridian | Aless damage than 94% | river and rain flooding | 1 |
| Boise City | B+less damage than 71% | river and rain flooding | 13 |
| Garden City | Bless damage than 55% | river and rain flooding | 8 |
| Eagle | B−less damage than 51% | river and rain flooding | 12 |
Hazard risk = FEMA’s expected yearly building damage per dollar of building value, vs. the 21,298 U.S. towns we grade; the map is shaded by fifths of the same scale. Flood claims = paid federal flood insurance claims on record.
Get ready for what Boise City 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.
- 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.
- Drop, cover and hold on.
- Strap tall furniture and the water heater to the wall.
- Know how to shut off the gas.
- 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 Boise City
Is Boise City at risk for natural disasters?
On FEMA’s National Risk Index, Boise City has lower expected damage per building than 71% of U.S. towns: B+ for hazard risk, #20 of 59 in Idaho. Most of the expected damage is river and rain flooding (66%) and wildfire (26%). This is FEMA’s model of an average year for today’s buildings, not a forecast.
Does Boise City flood?
Flood insurance has paid 13 claims in Boise City since 1979, $80K in all, or 0.1 per 1,000 homes, fewer than 99% of U.S. towns with a flood insurance record.
Is Boise City 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 Ada County, 25% of homes in mapped flood zones carry federal flood insurance, and 0.9% of all homes do.
How much is flood insurance in Boise City?
FEMA’s Community Rating System list shows no discount for Boise City’s flood program. Premiums depend on the building; policies usually start 30 days after you buy, so get a quote early.
Is Boise City at risk from river and rain flooding?
It is the largest share of the building damage FEMA expects here (66%), and Boise City’s rate for it is lower than 58% of U.S. census tracts.
Storm stories
Memories, warnings and help from neighbors in Boise City.
Sources: FEMA National Risk Index v1.20 (December 2025), census-tract table, combined by where Boise City’s 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.