Enter any address in Polk County, Iowa to see its FEMA flood zone
Flash flooding from disorganized storms is a notable hazard in Polk County, IA. Over the past 30 years, NOAA Storm Events data shows 177 flood events and 118 flash flood events, with 3 reported fatalities attributed to flash flooding. For instance, disorganized storms on July 20, 2025, produced heavy rainfall, and a period of rainfall from May 20-25, 2024, also led to flash flooding.
National Flood Insurance Program (NFIP) claims data indicates that properties in Zone A have experienced the most claims, with an average payout of $18,722 and an average water depth of 1.7 feet. However, properties in Zone X have seen significantly higher average payouts ($51,289) with an average water depth of 3.0 feet, suggesting that even areas outside of high-risk zones can experience substantial flood damage. Homeowners in Zone A, as well as those in Zone X, should pay close attention to flood risk.
Summary generated from NOAA storm narratives and NFIP claim data for this county. Not predictive.
251 NOAA storm reports from this county describe what happened, in the words of the meteorologists who were there.
Polk County, Iowa has recorded 295 flood-related events since 1996 according to NOAA's Storm Events Database, including 118 flash floods and 177 river or area floods. The county has received 20 federal disaster declarations, 8 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 And Tornadoes | Tornado | Apr 26, 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 Storms, Tornadoes, Straight-line Winds, And Flooding | Severe Storm | Jun 6, 2018 |
| Severe Storms, Flooding, And Tornadoes | Severe Storm | Jun 1, 2010 |
| 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 |
|---|---|---|
| Flash Flood | Jul 20, 2025 | 20.00K |
| Flood | May 24, 2024 | 0.00K |
| Flood | May 22, 2024 | 0.00K |
| Flash Flood | Apr 22, 2022 | 0.00K |
| Flash Flood | Aug 19, 2022 | 10.00K |
| Flood | Jun 7, 2022 | 0.00K |
| Flash Flood | Jun 22, 2020 | 0.00K |
| Flood | May 24, 2019 | 100.00K |
| Flood | May 24, 2019 | 50.00K |
| Flood | Jun 23, 2019 | 0.00K |
Flash Flood — Jul 20, 2025
Diurnally driven afternoon storms on Sunday, July 20th, 2025, developed within an unstable environment with CAPE values over 3000 J/kg and 40 to 45 kts of effective shear. Despite this unstable and decently sheared environment, several factors limited the severe weather potential, including weak low-level flow, a warm layer aloft, and an overall lack of forcing. This led to disorganized storms ...
Flood — May 24, 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 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, ...
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 — Aug 19, 2022
A surface low sinking south into the area allowed for scattered storms to develop across central Iowa in the afternoon. Steep lapse rates and deep layer shear allowed for the development of organized updrafts while low melting levels supported larger hail development. Several storms strengthened and prompted warnings, though few resulted in any severe reports. The strongest quickly developed ov...
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 Polk 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 Polk 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.