Enter any address in Cassia County, Idaho to see its FEMA flood zone
Flash flooding from heavy rainfall events is the dominant flood character in Cassia County. Over the past 30 years, the NOAA Storm Events Database has recorded 22 flash flood events, resulting in one fatality. Additionally, three broader flood events have been documented.
Recent historical events illustrate these risks. In January 2017, an atmospheric river event brought heavy snow followed by rain, leading to flooding and road closures, prompting an emergency declaration in Cassia County. Earlier that year, in February 2017, above-normal temperatures caused extensive flooding across several counties, including Cassia, due to rapid snowmelt. In September 2013, flash flooding occurred south of Oakley in Cassia County following localized heavy rainfall.
Residents in Zone A, which has seen an NFIP claim with an average payout of $6,751 and an average water depth of 0.0 ft, should pay particular attention to flood risks.
Summary generated from NOAA storm narratives and NFIP claim data for this county. Not predictive.
4 NOAA storm reports from this county describe what happened, in the words of the meteorologists who were there.
Cassia County, Idaho has recorded 25 flood-related events since 1996 according to NOAA's Storm Events Database, including 22 flash floods and 3 river or area floods. The county has received 5 federal disaster declarations, 2 of which involved flooding or coastal storms. Enter any address above to check its FEMA flood zone designation.
FEMA Disaster Declarations (1964–2020)
Source: OpenFEMA Disaster Declarations Summaries.
| Declaration | Type | Date |
|---|---|---|
| Covid-19 | Biological | Jan 20, 2020 |
| Covid-19 Pandemic | Biological | Jan 20, 2020 |
| Severe Winter Storms And Flooding | Flood | Feb 5, 2017 |
| Hurricane Katrina | Hurricane | Aug 29, 2005 |
| Heavy Rains & Flooding | Flood | Dec 31, 1964 |
NOAA Storm Events Database (1996–2025)
Source: NOAA National Weather Service Storm Events Database.
| Type | Date | Damage |
|---|---|---|
| Flash Flood | May 24, 2023 | 0.00K |
| Flash Flood | Jul 31, 2021 | 0.00K |
| Flash Flood | Jul 30, 2021 | 0.00K |
| Flood | Jan 8, 2017 | 0.00K |
| Flood | Feb 4, 2017 | 5.24M |
| Flood | Mar 1, 2017 | 175.00K |
| Flash Flood | Sep 3, 2013 | 6.00K |
| Flash Flood | Sep 2, 2013 | 4.00K |
| Flash Flood | Jul 4, 2009 | 0.00K |
| Flash Flood | May 16, 2005 | 110K |
Flash Flood — May 24, 2023
Widespread large hail was reported in parts of southeast Idaho.
Flash Flood — Jul 31, 2021
Sustained monsoonal flow brought more flooding to southeast Idaho on July 31st.
Flash Flood — Jul 30, 2021
Sustained monsoonal flow brought heavy rains and several areas with flash flooding.
Flood — Jan 8, 2017
A long dawn out atmospheric river event brought a variety of impacts to southeast Idaho including extremely heavy mountain snow, valley snow then rain on snow leading to flooding and roads covered with ice in the Snake River Plain, and many mountain avalanches. Many roads were closed for extended periods due to the heavy snow and avalanches. Custer County was declared a disaster area due to...
Flood — Feb 4, 2017
A trend toward above normal temperatures in February after extreme snowfall amounts in both December and January led to extensive flooding issues during the entirety of the month. The brunt of the flooding occurred in Cassia, Minidoka, Jefferson, Lincoln and Bingham Counties but all counties did receive at least minor flooding. The floding began February 4th and continued to affect low lying...
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 Cassia County, Idaho:
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 Cassia County, Idaho 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.