FEMA puts Onalaska’s expected hazard damage per building below that of 67% of U.S. towns, mostly from river and rain flooding
On FEMA’s National Risk Index, Onalaska gets a B+ for hazard risk: lower expected damage per building than 67% of U.S. towns, #243 of 362 in Wisconsin. Most of that expected damage is river and rain flooding (75%), then hail (13%). Flood insurance has paid 4 claims here since 1978.
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 Onalaska 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
Hail
Tornadoes
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 Onalaska’s grade
River and rain flooding is 75% of the building damage FEMA expects in Onalaska, and Onalaska’s rate of river and rain flooding damage is lower than 52% of U.S. census tracts. Hail adds 13%, at a rate in the top 8% of U.S. census tracts.
B+ #243 of 362 in Wisconsin; lower expected damage per building than 67% of U.S. towns (21,298).
Onalaska’s residents live in 7 census tracts; FEMA’s figures are combined by where they live.
The typical Wisconsin town has lower expected damage than 79% of U.S. towns; within the state, Onalaska has more expected damage per building than 67% of Wisconsin towns.
In dollars, FEMA expects about $2.8M a year in losses across Onalaska: $1.4M to buildings, the rest to people and crops.
Does Onalaska flood? Rarely: 4 flood claims since 1978
Every paid claim on a federal flood insurance policy in Onalaska, from FEMA’s records: 1.7 per 1,000 homes, fewer than 65% of the 13,809 U.S. towns with a flood insurance record.
Onalaska isn’t in FEMA’s Community Rating System, which cuts flood insurance up to 45% in towns that do extra flood-proofing.
Insurance rates: La Crosse County.2 federal disasters brought FEMA money to Onalaska
Disasters that paid out in Onalaska itself (aid to households or repair grants to the Town of Onalaska), newest first, with that year’s flood claims.
- 2017Severe Storms, Straight-line Winds, Flooding, Landslides, and Mud$142K to the Town of Onalaska for repairs1 flood claim paid that year
- 2001Flooding, Severe Storms and Tornadoes$4K to the Town of Onalaska for repairs
La Crosse County has had 15 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.
Old photos of Onalaska after a storm or flood belong in the town’s history. Add one, or share what you remember below.
Add to the Onalaska archive →Onalaska and its neighbors
Onalaska is 7th of the 9 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 |
|---|---|---|---|
| Onalaska | Aless damage than 86% | river and rain flooding | 2 |
| Medary | B+less damage than 74% | river and rain flooding | 1 |
| La Crosse | B+less damage than 74% | river and rain flooding | 76 |
| Holland | B+less damage than 69% | river and rain flooding | — |
| Holmen | B+less damage than 69% | river and rain flooding | 2 |
| Campbell | B+less damage than 68% | river and rain flooding | 1 |
| Onalaska | B+less damage than 67% | river and rain flooding | 4 |
| Hamilton | Bless damage than 56% | river and rain flooding | 3 |
| Farmington | C+more damage than 64% | river and rain flooding | — |
| New Hartford Township | — | 817 residents; we grade 1,000+ | |
| Richmond Township | — | 478 residents; we grade 1,000+ | |
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 Onalaska 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.
- Park in a garage or under cover when storms are forecast.
- Stay away from windows while it falls.
- Photograph roof and car damage for your insurer.
- Pick your spot now: the lowest floor, an inside room, no windows.
- A watch means be ready; a warning means take cover now.
- Keep shoes and a flashlight by the bed.
- 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 Onalaska
Is Onalaska at risk for natural disasters?
On FEMA’s National Risk Index, Onalaska has lower expected damage per building than 67% of U.S. towns: B+ for hazard risk, #243 of 362 in Wisconsin. Most of the expected damage is river and rain flooding (75%) and hail (13%). This is FEMA’s model of an average year for today’s buildings, not a forecast.
Does Onalaska flood?
Flood insurance has paid 4 claims in Onalaska since 1978, $34K in all, or 1.7 per 1,000 homes, fewer than 65% of U.S. towns with a flood insurance record.
Is Onalaska 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 La Crosse County, 31% of homes in mapped flood zones carry federal flood insurance, and 1.2% of all homes do.
How much is flood insurance in Onalaska?
FEMA’s Community Rating System list shows no discount for Onalaska’s flood program. Premiums depend on the building; policies usually start 30 days after you buy, so get a quote early.
What was the biggest storm in Onalaska?
By FEMA money that reached Onalaska, Severe Storms, Straight-line Winds, Flooding, Landslides, and Mud (2017): $142K to the Town of Onalaska for repairs.
Is Onalaska at risk from river and rain flooding?
It is the largest share of the building damage FEMA expects here (75%), and Onalaska’s rate for it is lower than 52% of U.S. census tracts.
Storm stories
Memories, warnings and help from neighbors in Onalaska.
Sources: FEMA National Risk Index v1.20 (December 2025), census-tract table, combined by where Onalaska’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.