Enter any address in St. Lawrence County, New York to see its FEMA flood zone
Flash flooding from heavy rainfall events dominates St. Lawrence County's flood history. Between 2004 and 2024, NOAA Storm Events data recorded 18 flood events and 17 flash flood events. For example, the remnants of Tropical Storm Debby in August 2024 produced 3 to 7 inches of rain across a wide area, leading to widespread flash flooding, damage to over 100 roads and several bridges, and some home damage.
National Flood Insurance Program (NFIP) claims data shows that properties in Zone A have experienced the most claims, with an average payout of $28,712 and an average water depth of 5.3 feet. Properties in Zone X and Zone X_Unshaded also show significant claim activity, with average payouts exceeding $8,000 and recorded water depths ranging from 2.6 feet to negative 4.3 feet.
Residents in areas designated as Zone A, as well as those in Zone X and Zone X_Unshaded, should pay particular attention to flood risk. Homeowners in these zones may face higher potential for flood damage and associated costs.
Summary generated from NOAA storm narratives and NFIP claim data for this county. Not predictive.
25 NOAA storm reports from this county describe what happened, in the words of the meteorologists who were there.
St. Lawrence County, New York has recorded 35 flood-related events since 1996 according to NOAA's Storm Events Database, including 17 flash floods and 18 river or area floods. The county has received 19 federal disaster declarations, 3 of which involved flooding or coastal storms. Enter any address above to check its FEMA flood zone designation.
FEMA Disaster Declarations (1990–2024)
Source: OpenFEMA Disaster Declarations Summaries.
| Declaration | Type | Date |
|---|---|---|
| Remnants Of Tropical Storm Debby | Tropical Storm | Aug 8, 2024 |
| Severe Storm, Tornadoes, And Flooding | Flood | Jul 10, 2024 |
| Severe Winter Storm And Snowstorm | Snowstorm | Dec 23, 2022 |
| Severe Winter Storm And Snowstorm | Winter Storm | Nov 18, 2022 |
| Covid-19 | Biological | Jan 20, 2020 |
| Covid-19 Pandemic | Biological | Jan 20, 2020 |
| Flooding | Flood | May 2, 2017 |
| Severe Winter Storm, Snowstorm, And Flooding | Snowstorm | Nov 17, 2014 |
| Hurricane Sandy | Hurricane | Oct 27, 2012 |
| Hurricane Katrina Evacuation | Hurricane | Aug 29, 2005 |
NOAA Storm Events Database (1996–2025)
Source: NOAA National Weather Service Storm Events Database.
| Type | Date | Damage |
|---|---|---|
| Flash Flood | Aug 9, 2024 | 1.50M |
| Flash Flood | Aug 9, 2024 | 3.00M |
| Flash Flood | Aug 9, 2024 | 500.00K |
| Flood | Aug 9, 2024 | 2.00M |
| Flash Flood | Aug 4, 2023 | 75.00K |
| Flash Flood | Dec 25, 2022 | 100.00K |
| Flash Flood | Jul 24, 2017 | 100.00K |
| Flash Flood | Jul 24, 2017 | 5.00K |
| Flood | Apr 15, 2014 | 4.10M |
| Flood | Apr 9, 2014 | 10.00K |
Flash Flood — Aug 9, 2024
The remnants of TS Debby tracked through St. Lawrence County during the afternoon/early evening of August 9, 2024. This produced a 50-75 mile swath of excessive rainfall from 3 to 7 inches which led to widespread flash flooding. Subsequent information indicated over 100 roads damaged or washed out with several bridges damaged and/or destroyed. Some flood damage to homes also occurred in a few l...
Flood — Aug 9, 2024
The remnants of TS Debby tracked through St. Lawrence County during the afternoon/early evening of August 9, 2024. This produced a 50-75 mile swath of excessive rainfall from 3 to 7 inches which led to widespread flash flooding. Subsequent information indicated over 100 roads damaged or washed out with several bridges damaged and/or destroyed. Some flood damage to homes also occurred in a few l...
Flash Flood — Aug 4, 2023
Persistent shower and thunderstorm activity affected portions of southern St. Lawrence County, NY during the late afternoon and evening hours on August 16, 2023. This led to areas of flash flooding, particularly in the Pitcairn, NY area.
Flash Flood — Dec 25, 2022
A large and intense storm system tracked through the region from December 23-25, 2022. Heavy rain and snowmelt led to rises on the Raquette River in St. Lawrence County. Some ice breakup was noted, some of which affected portions of the Town of Pierrepoint, NY on the 25th where high water affected several homes.
Flash Flood — Jul 24, 2017
An upper level trough widespread showers over northern New York county as an stationary band developed across west-central Saint Lawrence that produced flash flooding. A narrow band of 4-7 inches of rain fell with the individual max being 6.9 inches at the NYS Mesonet gauge in Hammond, NY.
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 St. Lawrence County, New York:
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 St. Lawrence County, New York 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.