Photo: Paul Sableman · CC BY 2.0More hazard damage per building is expected in Affton than in 68% of U.S. towns, mostly from river and rain flooding
On FEMA’s National Risk Index, Affton gets a C for hazard risk: higher expected damage per building than 68% of U.S. towns, #149 of 247 in Missouri. Most of that expected damage is river and rain flooding (60%), then earthquakes (25%). Flood insurance has paid 32 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 Affton 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
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 Affton’s grade
River and rain flooding is 60% of the building damage FEMA expects in Affton, and Affton’s rate of river and rain flooding damage is higher than 61% of U.S. census tracts. Hail adds 10%, at a rate in the top 6% of U.S. census tracts.
C #149 of 247 in Missouri; higher expected damage per building than 68% of U.S. towns (21,298).
Affton’s residents live in 8 census tracts; FEMA’s figures are combined by where they live.
The typical Missouri town has higher expected damage than 59% of U.S. towns; within the state, Affton has more expected damage per building than 60% of Missouri towns.
In dollars, FEMA expects about $13.3M a year in losses across Affton: $5.6M to buildings, the rest to people and crops.
Does Affton flood? Sometimes: 32 flood claims since 1979
Every paid claim on a federal flood insurance policy in Affton, from FEMA’s records: 3.5 per 1,000 homes, more than 52% of the 13,809 U.S. towns with a flood insurance record.
- Hurricane Ike5 claims · $221K
- The Midwest Flooding1 claim · $6K
Affton isn’t in FEMA’s Community Rating System, which cuts flood insurance up to 45% in towns that do extra flood-proofing.
Insurance rates: St. Louis County.3 federal disasters brought FEMA money to Affton
Disasters that paid out in Affton itself (aid to households or repair grants to Affton), newest first, with that year’s flood claims.
- 2022Severe Storms and Flooding4 households applied for aid$57K aid approved1 flood claim paid that year
- 2015Severe Storms, Tornadoes, Straight-line Winds, and Flooding3 households applied for aid$2K aid approved
- 2008Severe Storms, Flooding, and a Tornado4 households applied for aid$2K aid approved5 flood claims paid that year
St. Louis County has had 30 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 Affton after a storm or flood belong in the town’s history. Add one, or share what you remember below.
Add to the Affton archive →Affton and its neighbors
Affton is 2nd 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 |
|---|---|---|---|
| Green Park | C+more damage than 57% | river and rain flooding | 8 |
| Affton | Cmore damage than 68% | river and rain flooding | 32 |
| Concord | Cmore damage than 69% | river and rain flooding | 1 |
| St. George | Cmore damage than 70% | river and rain flooding | — |
| Mehlville | Cmore damage than 74% | river and rain flooding | 12 |
| Crestwood | Cmore damage than 74% | river and rain flooding | 33 |
| Marlborough | C−more damage than 77% | river and rain flooding | — |
| Lemay | C−more damage than 84% | river and rain flooding | 135 |
| Lakeshire | Dmore damage than 87% | river and rain flooding | 2 |
| Grantwood Village | — | not graded yet | |
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 Affton 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.
- 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 Affton
Is Affton at risk for natural disasters?
On FEMA’s National Risk Index, Affton has higher expected damage per building than 68% of U.S. towns: C for hazard risk, #149 of 247 in Missouri. Most of the expected damage is river and rain flooding (60%) and earthquakes (25%). This is FEMA’s model of an average year for today’s buildings, not a forecast.
Does Affton flood?
Flood insurance has paid 32 claims in Affton since 1979, $381K in all, or 3.5 per 1,000 homes, more than 52% of U.S. towns with a flood insurance record. The most claims came from Hurricane Ike (5).
Is Affton 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 St. Louis County, 34% of homes in mapped flood zones carry federal flood insurance, and 0.6% of all homes do.
How much is flood insurance in Affton?
FEMA’s Community Rating System list shows no discount for Affton’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 Affton?
By FEMA money that reached Affton, Severe Storms and Flooding (2022): 4 households applied for aid, $57K approved. By flood claims, Hurricane Ike: 5 paid, $221K.
Is Affton at risk from river and rain flooding?
It is the largest share of the building damage FEMA expects here (60%), and Affton’s rate for it is higher than 61% of U.S. census tracts.
Storm stories
Memories, warnings and help from neighbors in Affton.
Sources: FEMA National Risk Index v1.20 (December 2025), census-tract table, combined by where Affton’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.