Natural hazards · Surprise Valley

Surprise Valley, SD natural hazards

Most of the natural-hazard damage FEMA expects in Surprise 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 Surprise Valley?

Moderate

vs. U.S. communities

FEMA expects yearly storm and flood damage to homes and buildings in Surprise Valley to be higher than in 55% of U.S. communities, mostly from inland flooding and cold waves.

Inland flooding35%Cold waves24%Wildfire19%Tornadoes7%Everything else15%

By hazard

What Surprise Valley faces

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

Inland flooding

35% of expected damage

Below average · higher than 48% of U.S. places

Recorded about once every 2 years in the area

Cold waves

24% of expected damage

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

Recorded about 5 times a year in the area

Wildfire

19% of expected damage

Well above average · higher than 98% of U.S. places

Tornadoes

7% of expected damage

Above average · higher than 65% of U.S. places

Recorded about once every 3 years in the area

Lower here

HailIce 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 Surprise Valley flood?

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

Disasters that hit Surprise Valley

Federal disasters declared here

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

Brought FEMA money into Surprise ValleyDeclared for Mellette County only

Mellette County has had 12 natural disasters declared since 1953, most often floods and severe storms.

Around Surprise Valley

Surprise Valley and the towns around it

Very lowLowModerateHighVery high

Surprise Valleymostly inland floodingModerate

Blackpipemostly inland floodingModerate

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