Natural hazards · Grenville

Grenville, SD natural hazards

Most of the natural-hazard damage FEMA expects in Grenville comes from inland flooding, and overall the risk is moderate for a U.S. community. Flood insurance has paid 7 claims here since 1996. 1 federal disaster brought FEMA money into town.

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

Expected damage

How exposed is Grenville?

Moderate

vs. U.S. communities

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

Inland flooding34%Cold waves27%Strong wind14%Tornadoes9%Wildfire5%Everything else11%

By hazard

What Grenville 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 39% of U.S. places

Recorded about once a year in the area

Cold waves

27% of expected damage

Above average · higher than 66% of U.S. places

Recorded about 14 times a year in the area

Strong wind

14% of expected damage

Well above average · higher than 92% of U.S. places

Recorded about 3 times a year in the area

Tornadoes

9% of expected damage

Well above average · higher than 87% of U.S. places

Recorded about once every 4 years in the area

Wildfire

5% of expected damage

Well above average · higher than 95% of U.S. places

Lower here

HailIce stormsWinter weatherHeat wavesEarthquakesLandslidesLightningDrought

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 Grenville flood?

Every paid claim on a federal flood insurance policy in Grenville, from FEMA’s records.

7paid claims since 1996

$204Kpaid to owners

1homes flooded more than once

19962026

Homes that flooded again and again

■ FEMA “severe repetitive loss” (0) ■ flooded 2+ times

of all homes
are insured

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

Insurance rates: Day County.

Disasters that hit Grenville

1 federal disaster brought FEMA money here

Disasters the President declared that paid out in Grenville itself: aid to households, or repair grants to the Town of Grenville.

Brought FEMA money into GrenvilleDeclared for Day County only

2005

Severe Winter Storm

$2K to the Town of Grenville for repairs

Day County has had 23 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. Grenville 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 Grenville’s own flood-insurance community; household aid to the registrant’s city; repair grants to the Town of Grenville. 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.