Enter any address in Marshall County, Iowa to see its FEMA flood zone
Flash flooding from heavy rainfall events is the primary flood concern in Marshall County. Between 2004 and 2024, NOAA Storm Events data recorded 67 flood events and 23 flash flood events in the county. For example, multiple rounds of heavy rainfall in May 2024 caused flash flooding across portions of northern and central Iowa, impacting Marshall County. Another event in May 2024 saw 4 to 6 inches of rainfall over a period of several days, leading to flash flooding.
National Flood Insurance Program (NFIP) claims data indicates that properties in Zone A and Zone X have experienced flood damage. Zone A properties, which are typically at higher risk, saw an average water depth of 1.9 feet. Zone X properties, generally considered to have a moderate risk, had an average water depth of 1.5 feet. Properties in Zone X_UNSHADED also had claims with an average water depth of 1.0 foot.
Homeowners and real estate agents should pay close attention to flood risk, particularly those in areas designated as Zone A or Zone X, as these zones have historically seen flood claims.
Summary generated from NOAA storm narratives and NFIP claim data for this county. Not predictive.
77 NOAA storm reports from this county describe what happened, in the words of the meteorologists who were there.
Marshall County, Iowa has recorded 90 flood-related events since 1996 according to NOAA's Storm Events Database, including 23 flash floods and 67 river or area floods. The county has received 20 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 (1965–2024)
Source: OpenFEMA Disaster Declarations Summaries.
| Declaration | Type | Date |
|---|---|---|
| Severe Storms, Tornadoes, And Flooding | Severe Storm | May 20, 2024 |
| Severe Storms | Severe Storm | Aug 10, 2020 |
| Covid-19 | Biological | Jan 20, 2020 |
| Covid-19 Pandemic | Biological | Jan 20, 2020 |
| Severe Storms And Flooding | Flood | Mar 12, 2019 |
| Severe Storm And Tornadoes | Severe Storm | Jul 19, 2018 |
| Severe Storms, Tornadoes, And Flooding | Severe Storm | May 19, 2013 |
| Severe Storms, Straight-line Winds, And Flooding | Severe Storm | Jul 9, 2011 |
| Severe Storms, Tornadoes, And Flooding | Severe Storm | May 25, 2008 |
| Severe Winter Storms | Severe Storm | Feb 23, 2007 |
NOAA Storm Events Database (1996–2025)
Source: NOAA National Weather Service Storm Events Database.
| Type | Date | Damage |
|---|---|---|
| Flood | May 22, 2024 | 0.00K |
| Flood | May 21, 2024 | 0.00K |
| Flash Flood | Apr 22, 2022 | 0.00K |
| Flash Flood | Jun 15, 2019 | 50.00K |
| Flood | Mar 14, 2019 | 2.00M |
| Flood | Mar 14, 2019 | 0.00K |
| Flood | Mar 14, 2019 | 200.00K |
| Flood | Oct 9, 2018 | 0.00K |
| Flood | Sep 2, 2018 | 50.00K |
| Flash Flood | Sep 2, 2018 | 20.00K |
Flood — May 22, 2024
There were several rounds of rainfall over the period starting around May 20 through around May 25. This is when there were two rounds of heavy rainfall along with severe thunderstorms including tornadoes and straight-line winds, detailed in respective severe entries for the month. 60-hour rainfall totals ending May 21 at 7pm were up to 4 to 6 inches over portions of Marshall, Tama, Poweshiek, ...
Flood — May 21, 2024
PLEASE NOTE, for tornadoes, please see separate Storm Data entry for May 21st. ||Multiple rounds of thunderstorms brought torrential rainfall, damaging winds, hail and destructive tornadoes to the state. These thunderstorms were the result of a low pressure system which lifted north into the area on the night of May 20th, 2024, producing slow moving storms that dropped 2 to 4 inches of rainfall...
Flash Flood — Apr 22, 2022
A warm front moved across the area late on the evening of April 21 into April 22. While thunderstorms remained below severe criteria, deep saturation and precipitable water values over 1.5 inches allowed for a band of heavier precipitation to set up over a narrow corridor in central Iowa. Several locations received over 3 inches of rain and a few areas saw flash flooding within towns, resulting...
Flash Flood — Jun 15, 2019
Increasingly humid conditions, a weak low pressure system, and an impinging northern weak cold front combined to create an environment ripe for strong to severe storms across northern and central Iowa, with much of the severe activity through central Iowa. ||The resulting environment from the aforementioned ingredients included SBCAPE values in the 2000-3000+ J/kg range, marginal effective bulk...
Flood — Mar 14, 2019
Reports from the 13h through the 19th in this entry. ||A relatively deep and widespread snowpack existed across the region during early to mid March. Many areas in central and northern Iowa had around a foot to two feet of snow on the ground, along with many areas in upstream river basins in Minnesota and the Dakotas having similar or deeper snowpacks on the ground. Additionally, with the below...
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 Marshall County, Iowa:
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 Marshall County, Iowa 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.