Alton’s biggest natural hazard is inland flooding
Most of the natural-hazard damage FEMA expects in Alton comes from inland flooding, and overall the risk is low for a U.S. community. Flood insurance has paid 5 claims here since 2024. 4 federal disasters brought FEMA money into town.
What stands out about Alton’s weather risks
Read from FEMA’s records below. The page puts what stands out first.
Does Alton flood? Rarely: 5 flood claims since 2024
Every paid claim on a federal flood insurance policy in Alton, from FEMA’s records.
- The June Midwest Flooding4 claims · $1.1M
- The Iowa Flooding1 claim · $150K
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: Sioux 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) and its biggest flood years.
- 2024Severe Storms, Flooding, Straight-Line Winds, and Tornadoes43 households applied for aid$375K aid approved$1.6M to the City of Alton for repairs5 flood claims paid that year
- 2019Severe Storms and Flooding$21K to the City of Alton for repairs
- 2013Severe Storms, Tornadoes, and Flooding$9K to the City of Alton for repairs
- 2009Severe Winter Storms and Snowstorm$5K to the City of Alton for repairs
Sioux County has had 13 natural disasters declared since 1953, most often severe storms and floods.
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 →How exposed is Alton?
FEMA expects yearly storm and flood damage to homes and buildings here to be higher than in 39% of U.S. communities, mostly from inland flooding and hail.
Calmer than 744 of the 1,026 Iowa towns we cover.
Alton is smaller than a census tract, so it shares the figures of the tract around its center.
What Alton faces
Each hazard’s share of the damage FEMA expects here, and how it compares with the rest of the country.
Inland flooding
Hail
Tornadoes
Cold waves
Drought
Get ready for what Alton actually faces
A short kit for its top hazards, 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.
Alton and its neighbors
How storm and flood risk compares across the town line. Tap a town to see its hazards.
| Town | Rating | Mostly | Flood claims |
|---|---|---|---|
| Alton | Low | inland flooding | 5 |
| Orange City | Low | tornadoes | 0 |
Rating = expected yearly storm and flood damage as a share of what’s there, vs. U.S. communities. Flood claims = paid federal flood insurance claims on record.
Most disasters here begin in April–June
The month each of Sioux County’s 13 declared disasters began, since 1953.
What these numbers can and can’t tell you
- An average, not a forecast. FEMA’s National Risk Index estimates the damage 18 kinds of natural hazards cause in a typical year, from decades of records and models. A quiet decade can follow a bad year.
- Compared by rate. “Higher than N%” compares yearly damage as a share of what’s there, so a big city isn’t rated riskier just for having more buildings.
- Money that reached town. Flood claims are matched to Alton’s own flood-insurance community; household aid to the registrant’s city; repair grants to the City of Alton.
- It follows property value. FEMA’s model weighs damage to buildings, so a place that recently lost many homes can rate lower than it feels.
Storm stories
Memories, warnings and help from neighbors in Alton.
Your answer becomes a post in Town Square.
Sources: FEMA National Risk Index (December 2025); 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. Census tracts: U.S. Census Bureau. Preparedness tips: Ready.gov. An average of past damage, not a forecast.