Natural hazards · Sioux Valley

Sioux Valley, SD natural hazards

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

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

Expected damage

How exposed is Sioux Valley?

Moderate

vs. U.S. communities

FEMA expects yearly storm and flood damage to homes and buildings in Sioux Valley to be higher than in 41% of U.S. communities, mostly from inland flooding and tornadoes.

Inland flooding33%Tornadoes25%Drought14%Hail13%Cold waves5%Everything else10%

By hazard

What Sioux Valley faces

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

Inland flooding

33% of expected damage

Below average · higher than 33% of U.S. places

Recorded about 4 times a year in the area

Tornadoes

25% of expected damage

Well above average · among the top 1% of U.S. places

Recorded about once every 4 years in the area

Drought

14% of expected damage

Recorded about 29 times a year in the area

Hail

13% of expected damage

Well above average · higher than 83% of U.S. places

Recorded about 7 times a year in the area

Cold waves

5% of expected damage

Above average · higher than 63% of U.S. places

Recorded about 6 times a year in the area

Lower here

Ice stormsWinter weatherHeat wavesWildfireEarthquakesLandslidesStrong windLightning

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 Sioux Valley flood?

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

of homes in flood zones
are insured

of all homes
are insured

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

Insurance rates: Union County.

Disasters that hit Sioux Valley

Federal disasters declared here

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

Brought FEMA money into Sioux ValleyDeclared for Union County only

Union County has had 15 natural disasters declared since 1953, most often floods and severe storms.

Around Sioux Valley

Sioux Valley and the towns around it

Very lowLowModerateHighVery high

Akronmostly inland floodingHigh

Sioux Valleymostly inland floodingModerate

Big Springsmostly inland floodingModerate

Spinkmostly inland floodingModerate

Virginiamostly inland floodingModerate

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