Enter any address in Sioux County, North Dakota to see its FEMA flood zone
6 NOAA storm reports from this county describe what happened, in the words of the meteorologists who were there.
Sioux County, North Dakota has recorded 14 flood-related events since 1996 according to NOAA's Storm Events Database, including 8 flash floods and 6 river or area floods. The county has received 22 federal disaster declarations, 9 of which involved flooding or coastal storms. Enter any address above to check its FEMA flood zone designation.
FEMA Disaster Declarations (1969–2025)
Source: OpenFEMA Disaster Declarations Summaries.
| Declaration | Type | Date |
|---|---|---|
| Severe Storm, Tornadoes, And Straight-line Winds | Severe Storm | Jun 20, 2025 |
| Severe Storm, Straight-line Winds, And Flooding | Severe Storm | Jun 7, 2021 |
| Covid-19 | Biological | Jan 20, 2020 |
| Covid-19 Pandemic | Biological | Jan 20, 2020 |
| Severe Winter Storm | Severe Storm | Oct 4, 2013 |
| Flooding | Flood | Apr 5, 2011 |
| Flooding | Flood | Feb 14, 2011 |
| Severe Winter Storm | Severe Storm | Apr 1, 2010 |
| Severe Winter Storm | Severe Storm | Jan 20, 2010 |
| Severe Storms And Flooding | Severe Storm | Mar 13, 2009 |
NOAA Storm Events Database (1996–2025)
Source: NOAA National Weather Service Storm Events Database.
| Type | Date | Damage |
|---|---|---|
| Flash Flood | Jul 8, 2019 | 750.00K (2 deaths) |
| Flash Flood | May 25, 2013 | 250.00K |
| Flood | Jun 2, 2011 | 250.00K |
| Flood | Jul 1, 2011 | 0.00K |
| Flood | Aug 1, 2011 | 0.00K |
| Flood | Mar 6, 2009 | 264.00K |
| Flood | Apr 1, 2009 | 166.00K |
| Flash Flood | Jun 7, 2005 | 70K |
| Flash Flood | Jun 7, 2005 | 18K |
| Flash Flood | Jun 7, 2005 | 50K |
Flash Flood — Jul 8, 2019
A surface boundary stretching from southwest into north central North Dakota served as the primary focal point for thunderstorm development in an atmosphere of very high instability. Initially, large hail was the main threat, though a couple of tornadoes developed in an area of enhanced low level shear. Later, storms mainly developed along an old outflow boundary and were slow moving. This comb...
Flash Flood — May 25, 2013
Tornado Watch number 217 was in effect during this event.||Thunderstorms developing in the afternoon, in the warm sector of an area of low pressure, continued into the evening as an upper level short wave trough moved into the Dakotas. While the tornado threat did materialize as predicted, steep mid-level lapse rates, Mean Layer CAPE over 2000 Joules/KG, and deep layer shear to 45 knots support...
Flood — Jun 2, 2011
This was part of historic flooding in North Dakota with statewide costs estimated around 1.5 billion dollars. Flooding was the result of significant winter snows and significant spring rains, not only in North Dakota but in Montana as well. Rocky Mountain snowpack was four to six times normal. Flooding was along the Missouri River from the Garrison Dam to the South Dakota border. Dams were over...
Flood — Jul 1, 2011
This was part of historic flooding in North Dakota with statewide costs estimated around 1.5 billion dollars. Flooding was the result of significant winter snows and significant spring rains, not only in North Dakota but in Montana as well. Rocky Mountain snowpack was four to six times normal. Flooding was along the Missouri River from the Garrison Dam to the South Dakota border. Dams were over...
Flood — Aug 1, 2011
This was part of historic flooding in North Dakota with statewide costs estimated around 1.5 billion dollars. Flooding was the result of significant winter snows and significant spring rains, not only in North Dakota but in Montana as well. Rocky Mountain snowpack was four to six times normal. Flooding was along the Missouri River from the Garrison Dam to the South Dakota border. Dams were over...
Source: NOAA National Weather Service Storm Events Database.
Source: OpenFEMA NFIP Individual Claims (2.25M records analyzed).
FEMA assigns flood zone designations to areas in Sioux County, North 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.
Properties in Sioux County, North 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.