Photo: Illinois2011 · CC BY 3.0On FEMA’s figures, Alton faces about as much hazard damage per building as the typical U.S. town, mostly from river and rain flooding
On FEMA’s National Risk Index, Alton gets a B− for hazard risk: higher expected damage per building than 53% of U.S. towns, #369 of 768 in Illinois. Most of that expected damage is river and rain flooding (62%), then earthquakes (21%). Flood insurance has paid 57 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 Alton 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
Tornadoes
Hail
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 Alton’s grade
River and rain flooding is 62% of the building damage FEMA expects in Alton, and Alton’s rate of river and rain flooding damage is higher than 51% of U.S. census tracts. Next is earthquakes at 21% (higher than 81% of U.S. census tracts).
B− #369 of 768 in Illinois; higher expected damage per building than 53% of U.S. towns (21,298).
Alton’s residents live in 14 census tracts; FEMA’s figures are combined by where they live.
The typical Illinois town has higher expected damage than 54% of U.S. towns; within the state, Alton has less expected damage per building than 52% of Illinois towns.
In dollars, FEMA expects about $13.8M a year in losses across Alton: $8.3M to buildings, the rest to people and crops.
Does Alton flood? Sometimes: 57 flood claims since 1979
Every paid claim on a federal flood insurance policy in Alton, from FEMA’s records: 4.5 per 1,000 homes, more than 58% of the 13,809 U.S. towns with a flood insurance record.
- The Early winter storms7 claims · $118K
- The Midwest Flooding7 claims · $328K
- The Mid-spring storms1 claim · $9K
Alton isn’t in FEMA’s Community Rating System, which cuts flood insurance up to 45% in towns that do extra flood-proofing.
Insurance rates: Madison County.4 federal disasters brought FEMA money to Alton
Disasters that paid out in Alton itself (aid to households or repair grants to the City of Alton), newest first, with that year’s flood claims.
- 2019Severe Storms and Flooding$5.7M to the City of Alton for repairs9 flood claims paid that year
- 2008Severe Storms and Flooding$383K to the City of Alton for repairs4 flood claims paid that year
- 2006Severe Winter Storm$245K to the City of Alton for repairs
- 2005Hurricane Katrina Evacuation$62K to the City of Alton for repairs
Madison County has had 13 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 Alton after a storm or flood belong in the town’s history. Add one, or share what you remember below.
Add to the Alton archive →Alton and its neighbors
Alton is 2nd of the 5 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 |
|---|---|---|---|
| Godfrey | B−less damage than 53% | river and rain flooding | 27 |
| Alton | B−more damage than 53% | river and rain flooding | 57 |
| Foster Township | C+more damage than 60% | river and rain flooding | 28 |
| Wood River Township | Cmore damage than 75% | river and rain flooding | 101 |
| East Alton | C−more damage than 78% | river and rain flooding | 5 |
| Alton Township | — | not graded yet | |
| West Alton | — | 467 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 Alton 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.
- 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.
- 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.
- 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 Alton
Is Alton at risk for natural disasters?
On FEMA’s National Risk Index, Alton has higher expected damage per building than 53% of U.S. towns: B− for hazard risk, #369 of 768 in Illinois. Most of the expected damage is river and rain flooding (62%) and earthquakes (21%). This is FEMA’s model of an average year for today’s buildings, not a forecast.
Does Alton flood?
Flood insurance has paid 57 claims in Alton since 1979, $1.4M in all, or 4.5 per 1,000 homes, more than 58% of U.S. towns with a flood insurance record. 9 properties have flooded more than once. The most claims came from Early winter storms (7).
Is Alton 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 Madison County, 0.8% of all homes carry federal flood insurance.
How much is flood insurance in Alton?
FEMA’s Community Rating System list shows no discount for Alton’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 Alton?
By FEMA money that reached Alton, Severe Storms and Flooding (2019): $5.7M to the City of Alton for repairs. By flood claims, Early winter storms: 7 paid, $118K.
Is Alton at risk from river and rain flooding?
It is the largest share of the building damage FEMA expects here (62%), and Alton’s rate for it is higher than 51% of U.S. census tracts.
Storm stories
Memories, warnings and help from neighbors in Alton.
Sources: FEMA National Risk Index v1.20 (December 2025), census-tract table, combined by where Alton’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.