Natural hazards · Irwin

Irwin, SD natural hazards

Most of the natural-hazard damage FEMA expects in Irwin 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 Irwin?

High

vs. U.S. communities

FEMA expects yearly storm and flood damage to homes and buildings in Irwin to be higher than in 69% of U.S. communities, mostly from inland flooding and cold waves.

Inland flooding44%Cold waves30%Tornadoes6%Hail5%Wildfire5%Everything else9%

By hazard

What Irwin faces

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

Inland flooding

44% of expected damage

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

Recorded about once a year in the area

Cold waves

30% of expected damage

Above average · higher than 62% of U.S. places

Recorded about 5 times a year in the area

Tornadoes

6% of expected damage

Well above average · higher than 75% of U.S. places

Recorded about once every 2 years in the area

Hail

5% of expected damage

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

Recorded about 4 times a year in the area

Wildfire

5% of expected damage

Well above average · higher than 96% of U.S. places

Lower here

Ice stormsWinter weatherHeat wavesEarthquakesLandslidesStrong windLightningDrought

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 Irwin flood?

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

of all homes
are insured

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

Insurance rates: Tripp County.

Disasters that hit Irwin

Federal disasters declared here

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

Brought FEMA money into IrwinDeclared for Tripp County only

Tripp County has had 18 natural disasters declared since 1953, most often floods and severe storms.

Around Irwin

Irwin and the towns around it

Very lowLowModerateHighVery high

Irwinmostly inland floodingHigh

Sullymostly inland floodingHigh

Ellistonmostly inland floodingHigh

Colomemostly inland floodingHigh

Edensmostly cold wavesModerate

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. Irwin 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 Irwin’s own flood-insurance community; household aid to the registrant’s city; repair grants to the Township of Irwin. 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.