FloodZoneMap.org

Day County, South Dakota Flood Zones

Check an Address in Day County

Enter any address in Day County, South Dakota to see its FEMA flood zone

The Flooding Character of Day County

Flash flooding from summer thunderstorms is a significant flood character for Day County. Recent events include heavy rainfall on June 25th, 2025, which caused washed-out roads and water reaching home foundations near Milbank. Additionally, on August 17th, 2025, intense rainfall on top of wet conditions led to flooding across several counties, with significant rain recorded near Lake Poinsett and Claremont.

National Flood Insurance Program (NFIP) claims data shows that properties in Zone A and Zone UNKNOWN have experienced higher average payouts and water depths compared to Zone X and Zone X_UNSHADED. Homeowners in areas designated as Zone A or Zone UNKNOWN, as well as those located near rivers or in low-lying areas, should pay the most attention to flood risk.

Summary generated from NOAA storm narratives and NFIP claim data for this county. Not predictive.

Read First-Hand Flood Stories from Day County

12 NOAA storm reports from this county describe what happened, in the words of the meteorologists who were there.

Read South Dakota flood stories →

Flood Risk Data for Day County

Day County, South Dakota has recorded 39 flood-related events since 1996 according to NOAA's Storm Events Database, including 11 flash floods and 25 river or area floods. The county has received 24 federal disaster declarations, 10 of which involved flooding or coastal storms. Enter any address above to check its FEMA flood zone designation.

Day County Disaster History

FEMA Disaster Declarations (1976–2023)

Disaster Declarations
24
Flood/Coastal Disasters
10
Latest Disaster
Flooding (2023-04-09)

Source: OpenFEMA Disaster Declarations Summaries.

Recent Disaster Declarations in Day County

DeclarationTypeDate
FloodingFloodApr 9, 2023
Severe Winter Storms And SnowstormWinter StormDec 12, 2022
Severe Storm, Straight-line Winds, Tornadoes, And FloodingSevere StormMay 12, 2022
Covid-19BiologicalJan 20, 2020
Covid-19 PandemicBiologicalJan 20, 2020
Severe Storms, Tornadoes, And FloodingSevere StormSep 9, 2019
Severe Winter Storm, Snowstorm, And FloodingFloodMar 13, 2019
Severe Winter StormSevere StormDec 24, 2016
FloodingFloodMar 11, 2011
FloodingFloodMar 10, 2010

Recorded Flood Events in Day County

NOAA Storm Events Database (1996–2025)

Total Flood Events
39
River/Area Floods
25
Flash Floods
11
Coastal/Storm Surge
3
Total Property Damage
$21.5M

Source: NOAA National Weather Service Storm Events Database.

Recent Flood Events in Day County

TypeDateDamage
FloodJun 26, 20250.00K
FloodAug 17, 20250.00K
FloodAug 13, 20250.00K
FloodApr 12, 2023150.00K
FloodMar 27, 20190.00K
FloodAug 2, 20190.00K
FloodMay 1, 20190.00K
FloodJun 1, 20190.00K
FloodApr 1, 2019104.30K
Flash FloodJun 19, 20140.00K

Day County Flood History

Flood — Jun 26, 2025

On June 25th, multiple thunderstorms from the morning into the early afternoon caused flooding in parts of northeast South Dakota. A CoCoRaHS observer 4 miles south-southeast of Milbank recorded 3.33 inches of rain, while the COOP observer in Milbank measured 3.25 inches. Grant County Emergency Management sent photos of washed-out roads, and a resident near Ortley documented water reaching a ho...

Flood — Aug 17, 2025

Brief but intense heavy rainfall from thunderstorms, on top of weeks of wet weather, resulted in additional flooding across Marshall, Hamlin, Codington, and Deuel counties starting on the 17th and persisting well into the 18th. An estimated 3 inches of rain fell in Lake Poinsett, while 1.63 inches was recorded by the COOP sensor 20 miles north northeast of Aberdeen, 1.62 inches was submitted b...

Flood — Aug 13, 2025

Two clusters of storms would move across the forecast area on the 13th into the early morning hours of the 14th. The day started with an isolated stronger storm generating 1 inch hail 6 miles north northeast of Lowry. That cluster would continue to move east and intensify, with 1.5 inch hail observed 8 miles east of Pierpont. These storms would damage siding and crops around Pierpont, with addi...

Flood — Apr 12, 2023

The snowfall during the season in northeast and central South Dakota exceeded normal levels, with many locations ranking among the top 10 for the snowiest seasons. Additionally, the late spring conditions were unusually cold, resulting in a persistent and exceptionally deep snowpack until early April. The depth of the snowpack ranged from 15 to 30 plus inches, containing approximately 4 to 8 in...

Flood — Mar 27, 2019

Much above normal winter snowfall and melt water/ice jams along with heavy rains in the middle of March brought flooding across parts of central and northeast South Dakota for late March. Rivers and creeks flooded across much of the area along with many fields and roads. The flooding damaged many of the roads and culverts across the region. Some structures were also flooded. Lake levels also ro...

Source: NOAA National Weather Service Storm Events Database.

Day County NFIP Flood Insurance Claims

Total Claims Filed
200
Total Paid Out
$2.9M
Avg Claim
$19,526
Avg Water Depth
2.2 ft

Claims by Flood Zone

A Zones (High Risk)
72
X Unshaded (Low)
12

Source: OpenFEMA NFIP Individual Claims (2.25M records analyzed).

Flood Zone Types in Day County

FEMA assigns flood zone designations to areas in Day County, South Dakota:

AE High Risk — 1% annual chance of flooding. Insurance required.

VE Very High Risk — Coastal flooding with wave action.

X (Shaded) Moderate Risk — 500-year floodplain.

X Low Risk — Outside major floodplains.

View all flood zone types →

Flood Insurance in Day County

Properties in Day County, South Dakota that are in FEMA-designated Special Flood Hazard Areas (zones A and V) with federally backed mortgages are required to carry flood insurance.

Even outside high-risk zones, flood insurance is recommended. From 2014 to 2024, nearly one-third of NFIP claims came from outside the high-risk Special Flood Hazard Area.

Visit FloodSmart.gov to find an agent and get a quote.