Natural hazards · River Sioux

River Sioux, IA natural hazards

Most of the natural-hazard damage FEMA expects in River Sioux comes from inland flooding, and overall the risk is high for a U.S. community.

FEMA National Risk Index, December 2025 · OpenFEMA claims, aid & declarations

Expected damage

How exposed is River Sioux?

High

vs. U.S. communities

FEMA expects yearly storm and flood damage to homes and buildings in River Sioux to be higher than in 74% of U.S. communities, mostly from inland flooding.

Inland flooding49%Drought14%Tornadoes13%Hail12%Strong wind5%Everything else7%

By hazard

What River Sioux faces

Each hazard’s share of the damage FEMA expects here, and how that compares with the rest of the country.

Inland flooding

49% of expected damage

Well above average · higher than 86% of U.S. places

Recorded about once a year in the area

Drought

14% of expected damage

Recorded about 23 times a year in the area

Tornadoes

13% of expected damage

Well above average · higher than 81% of U.S. places

Recorded about once every 7 years in the area

Hail

12% of expected damage

Well above average · higher than 91% of U.S. places

Recorded about 6 times a year in the area

Strong wind

5% of expected damage

Well above average · higher than 93% of U.S. places

Recorded about 4 times a year in the area

Lower here

Ice stormsWinter weatherCold wavesHeat wavesWildfireEarthquakesLandslidesLightning

Not a risk here

Coastal floodingHurricanesAvalanchesTsunamisVolcanic activity

Flood risk changes street by street. Check a specific address on FEMA’s flood map, and ask about flood insurance before you buy.

Flood insurance claims

Does River Sioux flood?

FEMA's records show no paid flood insurance claims in River Sioux.

of homes in flood zones
are insured

of all homes
are insured

No community discount. River Sioux isn’t in FEMA’s Community Rating System, which cuts flood insurance up to 45% in towns that do extra flood-proofing.

Insurance rates: Harrison County.

Disasters that hit River Sioux

Federal disasters declared here

None of the disasters declared for Harrison County shows FEMA aid or repair money reaching River Sioux itself in FEMA’s records.

Brought FEMA money into River SiouxDeclared for Harrison County only

Harrison County has had 21 natural disasters declared since 1953, most often severe storms and floods.

About these numbers

How to read this page

An average, not a forecastFEMA’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 here, so a big city isn’t rated riskier just for having more buildings. River Sioux is smaller than a census tract, so it shares the figures of the tract around its center.

Money that reached townFlood claims are matched to River Sioux’s own flood-insurance community; household aid to the registrant’s city; repair grants to River Sioux. FEMA’s model follows property values, so a place that recently lost many homes can rate lower than it feels.

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.