Natural hazards · Union

Union, SD natural hazards

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

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

Expected damage

How exposed is Union?

Low

vs. U.S. communities

FEMA expects yearly storm and flood damage to homes and buildings in Union to be higher than in 37% of U.S. communities, mostly from inland flooding and tornadoes.

Inland flooding34%Tornadoes23%Ice storms12%Hail8%Cold waves8%Strong wind6%Everything else10%

By hazard

What Union faces

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

Inland flooding

34% of expected damage

Below average · higher than 29% of U.S. places

Recorded about 2 times a year in the area

Tornadoes

23% of expected damage

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

Recorded about once every 3 years in the area

Ice storms

12% of expected damage

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

Recorded about once a year in the area

Hail

8% of expected damage

Well above average · higher than 78% of U.S. places

Recorded about 5 times a year in the area

Cold waves

8% of expected damage

Below average · higher than 34% of U.S. places

Recorded about 11 times a year in the area

Strong wind

6% of expected damage

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

Recorded about 4 times a year in the area

Lower here

Winter weatherHeat 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 Union flood?

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

of homes in flood zones
are insured

of all homes
are insured

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

Insurance rates: Moody County.

Disasters that hit Union

Federal disasters declared here

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

Brought FEMA money into UnionDeclared for Moody County only

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

Around Union

Union and the towns around it

Very lowLowModerateHighVery high

Flandreaumostly inland floodingHigh

Troymostly inland floodingModerate

Altonamostly inland floodingModerate

Unionmostly inland floodingLow

Wardmostly inland floodingLow

Lone Rockmostly inland floodingLow

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