FEMA expects less hazard damage per building in Sun Prairie than in 92% of U.S. towns, mostly from river and rain flooding
On FEMA’s National Risk Index, Sun Prairie gets an A for hazard risk: lower expected damage per building than 92% of U.S. towns. Most of that expected damage is river and rain flooding (84%). FEMA’s files show no paid flood insurance claims here.
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 Sun Prairie 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
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 Sun Prairie’s grade
River and rain flooding is 84% of the building damage FEMA expects in Sun Prairie, and Sun Prairie’s rate of river and rain flooding damage is lower than 71% of U.S. census tracts. Wildfire adds 6%, at a rate in the top 9% of U.S. census tracts.
A lower expected damage per building than 92% of U.S. towns (21,298).
All of Sun Prairie’s residents live in one census tract; the figures are that tract’s.
In dollars, FEMA expects about $922K a year in losses across Sun Prairie: $342K to buildings, the rest to people and crops.
Does Sun Prairie flood? No paid flood claims on record
FEMA’s records show no paid flood insurance claims in Sun Prairie. That’s not a promise: most homes don’t carry flood insurance, so small floods go unrecorded.
Sun Prairie isn’t in FEMA’s Community Rating System, which cuts flood insurance up to 45% in towns that do extra flood-proofing.
Insurance rates: Cascade County.The storms Sun Prairie remembers
None of the 4 disasters declared for Cascade County shows FEMA aid or repair money reaching Sun Prairie itself in FEMA’s records, so these are its biggest flood-claim years.
Cascade County has had 4 natural disasters declared by the President since 1953, most often severe storms, then floods. Not counted: the 2005 Hurricane Katrina evacuee emergency, which covered counties that took in evacuees.
Sun Prairie and its neighbors
Sun Prairie has the lowest expected damage per building of the 2 graded towns here. Tap a town to see its hazards.
| Town | Hazard risk | Mostly (buildings) | Flood claims |
|---|---|---|---|
| Sun Prairie | Aless damage than 92% | river and rain flooding | 0 |
| Vaughn | C+more damage than 63% | river and rain flooding | — |
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 Sun Prairie 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.
- 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 Sun Prairie
Is Sun Prairie at risk for natural disasters?
On FEMA’s National Risk Index, Sun Prairie has lower expected damage per building than 92% of U.S. towns: A for hazard risk. Most of the expected damage is river and rain flooding (84%) and wildfire (6%). The figures are for the one census tract the town shares with its neighbors. This is FEMA’s model of an average year for today’s buildings, not a forecast.
Is Sun Prairie 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 Cascade County, 12% of homes in mapped flood zones carry federal flood insurance, and 0.7% of all homes do.
How much is flood insurance in Sun Prairie?
FEMA’s Community Rating System list shows no discount for Sun Prairie’s flood program. Premiums depend on the building; policies usually start 30 days after you buy, so get a quote early.
Is Sun Prairie at risk from river and rain flooding?
It is the largest share of the building damage FEMA expects here (84%), and Sun Prairie’s rate for it is lower than 71% of U.S. census tracts.
Storm stories
Memories, warnings and help from neighbors in Sun Prairie.
Sources: FEMA National Risk Index v1.20 (December 2025), census-tract table, combined by where Sun Prairie’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.