Photo: Cbradshaw · CC BY-SA 3.0On FEMA’s figures, Mercer faces less hazard damage per building than 74% of U.S. towns, mostly from river and rain flooding
On FEMA’s National Risk Index, Mercer gets a B+ for hazard risk: lower expected damage per building than 74% of U.S. towns. Most of that expected damage is river and rain flooding (91%). Flood insurance has paid 2 claims here since 2013.
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 Mercer 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
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 Mercer’s grade
River and rain flooding is 91% of the building damage FEMA expects in Mercer, and Mercer’s rate of river and rain flooding damage is higher than 55% of U.S. census tracts. Lightning adds 2%, at a rate in the top 1% of U.S. census tracts.
B+ lower expected damage per building than 74% of U.S. towns (21,298).
Mercer’s residents live in 2 census tracts; FEMA’s figures are combined by where they live.
In dollars, FEMA expects about $1.3M a year in losses across Mercer: $749K to buildings, the rest to people and crops.
Does Mercer flood? Rarely: 2 flood claims since 2013
Every paid claim on a federal flood insurance policy in Mercer, from FEMA’s records: 1.1 per 1,000 homes, fewer than 76% of the 13,809 U.S. towns with a flood insurance record.
Mercer isn’t in FEMA’s Community Rating System, which cuts flood insurance up to 45% in towns that do extra flood-proofing.
Insurance rates: Iron County.3 federal disasters brought FEMA money to Mercer
Disasters that paid out in Mercer itself (aid to households or repair grants to the Town of Mercer), newest first, with that year’s flood claims.
- 2018Severe Storms, Straight-line Winds, and Flooding$12K to the Town of Mercer for repairs
- 2001Flooding, Severe Storms and Tornadoes$4K to the Town of Mercer for repairs
- 1999Wi-flood-07/20/99$1K to the Town of Mercer for repairs
Iron County has had 9 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 Mercer after a storm or flood belong in the town’s history. Add one, or share what you remember below.
Add to the Mercer archive →Mercer and its neighbors
Mercer has the lowest expected damage per building of the 1 graded towns here. Tap a town to see its hazards.
| Town | Hazard risk | Mostly (buildings) | Flood claims |
|---|---|---|---|
| Mercer | B+less damage than 74% | river and rain flooding | 2 |
| Sherman | — | 381 residents; we grade 1,000+ | |
| Oma | — | 309 residents; we grade 1,000+ | |
| Knight | — | 161 residents; we grade 1,000+ | |
| Carey | — | 291 residents; we grade 1,000+ | |
| Agenda | — | 492 residents; we grade 1,000+ | |
| Winchester | — | 542 residents; we grade 1,000+ | |
| Manitowish Waters | — | 768 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 Mercer 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.
- 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 Mercer
Is Mercer at risk for natural disasters?
On FEMA’s National Risk Index, Mercer has lower expected damage per building than 74% of U.S. towns: B+ for hazard risk. Most of the expected damage is river and rain flooding (91%). This is FEMA’s model of an average year for today’s buildings, not a forecast.
Does Mercer flood?
Flood insurance has paid 2 claims in Mercer since 2013, $15K in all, or 1.1 per 1,000 homes, fewer than 76% of U.S. towns with a flood insurance record.
Is Mercer 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 Iron County, 0.4% of all homes carry federal flood insurance.
How much is flood insurance in Mercer?
FEMA’s Community Rating System list shows no discount for Mercer’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 Mercer?
By FEMA money that reached Mercer, Severe Storms, Straight-line Winds, and Flooding (2018): $12K to the Town of Mercer for repairs.
Is Mercer at risk from river and rain flooding?
It is the largest share of the building damage FEMA expects here (91%), and Mercer’s rate for it is higher than 55% of U.S. census tracts.
Storm stories
Memories, warnings and help from neighbors in Mercer.
Sources: FEMA National Risk Index v1.20 (December 2025), census-tract table, combined by where Mercer’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.