Enter any address in Stephenson County, Illinois to see its FEMA flood zone
Flash flooding from thunderstorms is the dominant flood hazard in Stephenson County. Over the past 30 years, NOAA Storm Events data shows 40 flash flood events and 16 general flood events. Recent examples include heavy rainfall in August 2022, which caused numerous road closures due to floodwaters. Another event on July 14, 2024, also brought heavy rainfall.
National Flood Insurance Program (NFIP) claims data indicates that properties in Zone A have experienced the most claims, with an average payout of $12,515 and an average water depth of 3.5 feet. However, properties in Zone X have seen higher average payouts ($34,322) despite lower average water depths (1.6 feet). 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.
24 NOAA storm reports from this county describe what happened, in the words of the meteorologists who were there.
Stephenson County, Illinois has recorded 56 flood-related events since 1996 according to NOAA's Storm Events Database, including 40 flash floods and 16 river or area floods. The county has received 14 federal disaster declarations, 4 of which involved flooding or coastal storms. Enter any address above to check its FEMA flood zone designation.
FEMA Disaster Declarations (1969–2020)
Source: OpenFEMA Disaster Declarations Summaries.
| Declaration | Type | Date |
|---|---|---|
| Covid-19 | Biological | Jan 20, 2020 |
| Covid-19 Pandemic | Biological | Jan 20, 2020 |
| Severe Storms And Flooding | Flood | Feb 24, 2019 |
| Severe Winter Storm And Snowstorm | Snowstorm | Jan 31, 2011 |
| Severe Storms And Flooding | Severe Storm | Jul 19, 2010 |
| Record Snow And Near Record Snow | Snowstorm | Feb 5, 2008 |
| Severe Storms And Flooding | Severe Storm | Aug 7, 2007 |
| Snow | Snowstorm | Nov 30, 2006 |
| Hurricane Katrina Evacuation | Hurricane | Aug 29, 2005 |
| Severe Storms And Flooding | Severe Storm | Jul 17, 1996 |
NOAA Storm Events Database (1996–2025)
Source: NOAA National Weather Service Storm Events Database.
| Type | Date | Damage |
|---|---|---|
| Flash Flood | Jul 14, 2024 | 0.00K |
| Flash Flood | Aug 8, 2022 | 0.00K |
| Flash Flood | Aug 7, 2022 | 0.00K |
| Flood | Mar 16, 2019 | 0.00K |
| Flash Flood | Sep 12, 2019 | 0.00K |
| Flash Flood | Sep 10, 2019 | 0.00K |
| Flood | Feb 19, 2018 | 0.00K |
| Flash Flood | Jun 18, 2018 | 0.00K |
| Flash Flood | Oct 6, 2018 | 0.00K |
| Flash Flood | Jun 28, 2017 | 0.00K |
Flash Flood — Jul 14, 2024
Severe thunderstorms produced wind damage and heavy rainfall as the storms sagged southeastward across northwest Illinois on the evening of July 14th. The strongest thunderstorms occurred from the Quad Cities southeastward through Henry County and into southern Bureau and Putnam Counties.
Flash Flood — Aug 8, 2022
Two rounds of showers and thunderstorms tracked from northeast Iowa into northern Illinois Sunday morning, and again early Monday morning, bringing torrential rain and occasional lightning to the region. Rainfall amounts over 2 inches were common northeast of a line from Cedar Rapids, to De Witt, to Prophetstown IL. The highest amounts between 5 and 11 inches fell in eastern Jo Daviess and St...
Flash Flood — Aug 7, 2022
Two rounds of showers and thunderstorms tracked from northeast Iowa into northern Illinois Sunday morning, and again early Monday morning, bringing torrential rain and occasional lightning to the region. Rainfall amounts over 2 inches were common northeast of a line from Cedar Rapids, to De Witt, to Prophetstown IL. The highest amounts between 5 and 11 inches fell in eastern Jo Daviess and St...
Flood — Mar 16, 2019
Significant flooding occurred across northwest Illinois during March of 2019. Moderate to major flooding was observed on Illinois tributary rivers due to snowmelt, saturated soils, and rainfall from March 9th to 12th. The higher crests occurred on the Rock and Pecatonica Rivers in Illinois during the 2nd and 3rd weeks of March.
Flash Flood — Sep 12, 2019
Heavy rain-producing showers and storms moved across areas north of Interstate 80 on September 11 and 12. The higher 2-day rainfall totals were between 3 and 6 inches. In addition to the heavy rain, thunderstorm winds caused damaged to some tree limbs. ||Flash flooding occurred in Stephenson County where flowing water over 4 inches deep flooded Highway 20 west of Freeport. The Pecatonica River...
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 Stephenson County, Illinois:
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 Stephenson County, Illinois 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.