Lower Connecticut River Valley Planning Region, Connecticut: Natural Disaster Risk and History
Lower Connecticut River Valley Planning Region, Connecticut has a Relatively Moderate natural-hazard risk rating in FEMA's National Risk Index (v1.20, December 2025): a score of 83.8 out of 100, higher than about 83% of US counties, with inland (river and flash) flooding, hurricanes and coastal flooding scoring highest of its 18 hazards and $63 million a year in expected losses.
OpenFEMA lists 31 federal disaster declarations that included Lower Connecticut River Valley Planning Region since 1978, not counting 2 for COVID-19; the latest is EM-3604-CT (Severe Storms, Flooding, and A Potential Dam Breach, declared 13 January 2024). NOAA's Storm Prediction Center recorded 10 tornadoes touching Lower Connecticut River Valley Planning Region from 1950 to 2025.
Live weather alerts for Connecticut All official warnings Latest FEMA declarations
Population 174,152 Buildings worth $40 billion Area 522 sq mi Risk rank in Connecticut 7 of 9 FIPS 09130
All 18 hazards, highest risk first
FEMA National Risk Index| Hazard | Risk rating | Score | Expected loss a year | How often | Events in record |
|---|---|---|---|---|---|
| Inland flooding | Relatively Moderate | 90.3 | $49 million | about 2.3 a year | 63 |
| Hurricane | Relatively Moderate | 87.7 | $6.6 million | about once every 4.9 years | 70 |
| Coastal flooding | Relatively Moderate | 79.6 | $2.6 million | about 3.8 a year | — |
| Earthquake | Relatively Low | 74.8 | $1.4 million | about once every 885 years | — |
| Ice storm | Relatively Moderate | 72.8 | $309,056 | about 1.7 a year | 100 |
| Landslide | Relatively Low | 72.5 | $8,967 | about once every 2.6 years | — |
| Winter weather | Relatively Moderate | 65.0 | $131,043 | about 13 a year | 216 |
| Lightning | Relatively Moderate | 59.4 | $394,590 | about 25 a year | 87,628 strikes |
| Strong wind | Relatively Moderate | 53.4 | $739,141 | about 2.3 a year | 79 |
| Wildfire | Very Low | 43.6 | $39,157 | rarer than once in 1,000 years | — |
| Tornado | Relatively Low | 43.3 | $1.2 million | about once every 7.3 years | 0 |
| Heat wave | Relatively Low | 42.2 | $310,911 | about 4.9 a year | 69 |
| Drought | Relatively Low | 35.3 | $51,228 | about once every 1.4 years | 112 |
| Cold wave | Relatively Low | 30.5 | $525,324 | about once every 1.1 years | 15 |
| Hail | Very Low | 11.1 | $43,509 | about 1.8 a year | 72 |
| Avalanche | Not Applicable | — | — | — | — |
| Tsunami | Insufficient Data | — | — | — | — |
| Volcanic activity | Not Applicable | — | — | — | — |
Score: FEMA's percentile among US counties that face the hazard (higher = more risk). Expected loss: FEMA's modelled average yearly loss to buildings, people (as a statistical value) and crops. How often: FEMA's annualised frequency of the hazard in the county; for some hazards it counts event-days, so it is a rough guide, not a forecast. "Not Applicable" means FEMA does not model that hazard here.
Federal disaster declarations 31
Most common: Hurricane 11, Severe Storm 10, Snowstorm 7, Flood 3.
| Decade | Declarations | Incident types |
|---|---|---|
| 1970s | 1 | Snowstorm |
| 1980s | 3 | Flood ×2, Hurricane |
| 1990s | 4 | Snowstorm ×2, Flood, Hurricane |
| 2000s | 6 | Snowstorm ×3, Severe Storm ×2, Hurricane |
| 2010s | 12 | Severe Storm ×7, Hurricane ×4, Snowstorm |
| 2020s | 5 | Hurricane ×4, Severe Storm |
The last 10
Widest declarations that included Lower Connecticut River Valley Planning Region
- Hurricane Henri (2021, EM-3564-CT): 9 Connecticut counties designated.
- Tropical Storm Isaias (2021, DR-4580-CT): 9 Connecticut counties designated.
- Tropical Storm Isaias (2020, EM-3535-CT): 9 Connecticut counties designated.
Named storms in its declarations: Hurricane Ida (2021), Hurricane Henri (2021), Tropical Storm Isaias (2021), Tropical Storm Isaias (2020), Hurricane Sandy (2012), Tropical Storm Irene (2011), Hurricane Irene (2011), Hurricane Katrina (2005), Hurricane Bob (1991), Hurricane Gloria (1985).
Not counted above: 2 COVID-19 ("Biological") declarations — in 2020 every US county was included. Connecticut also had 2 statewide declarations with no county list.
Tornado record since 1950 10
| Tornadoes touching the county | 10 |
|---|---|
| Strongest-rated | (E)F3 ×1 |
| Peak month | June (4) |
| Deadliest | 21 Aug 1951, F3, 0.1 mi path, 0 killed, 8 injured |
| Longest path | 19 Jul 1963, F1, 12.3 mi path |
| Most recent | 31 Jul 2009, EF1, 2.9 mi path |
| Deaths / injuries on those paths | 0 / 8 |
| Rating | (E)F0 | (E)F1 | (E)F2 | (E)F3 | (E)F4 | (E)F5 | Unrated |
|---|---|---|---|---|---|---|---|
| Count | 2 | 6 | 1 | 1 | 0 | 0 | 0 |
| Decade | 1950s | 1960s | 1970s | 1980s | 1990s | 2000s | 2010s | 2020s |
|---|---|---|---|---|---|---|---|---|
| Count | 2 | 1 | 2 | 1 | 3 | 1 | 0 | 0 |
Deaths and injuries are for each tornado's whole path, which can run beyond this county. F-scale ratings before February 2007, Enhanced Fujita (EF) after.
How Lower Connecticut River Valley Planning Region compares with its 5 nearest counties
| County | Distance | Overall risk | Score | Top hazard |
|---|---|---|---|---|
| Lower Connecticut River Valley Planning Region (this page) | — | Relatively Moderate | 83.8 | Inland flooding |
| South Central Connecticut Planning Region | 30 km | Relatively High | 95.1 | Hurricane |
| Southeastern Connecticut Planning Region | 34 km | Relatively Moderate | 88.6 | Hurricane |
| Capitol Planning Region | 41 km | Relatively High | 97.4 | Inland flooding |
| Naugatuck Valley Planning Region | 49 km | Relatively Moderate | 93.2 | Inland flooding |
| Northeastern Connecticut Planning Region | 61 km | Relatively Low | 62.8 | Hurricane |
Nearest by distance between county centres. Every county in Connecticut, ranked.
Vulnerability and resilience
| Social vulnerability | Very Low 17.9 |
|---|---|
| Community resilience | Very High 90.4 |
| Community risk factor | 0.86 |
| Expected annual loss, all hazards | $63 million |
FEMA scales expected losses up where social vulnerability is high (people who may find it harder to prepare, evacuate or recover) and down where community resilience is high. A factor above 1 raises the risk score. For social vulnerability a high rating is worse; for resilience a high rating is better.
Prepare for Lower Connecticut River Valley Planning Region's main hazards
- Right now: National Weather Service alerts for Connecticut · all official warnings on Global Incident Tracker.
- Inland flooding: Flood safety: why shallow water kills · Floods recorded
- Hurricane: Is there a hurricane now? · Cyclone preparation
- Coastal flooding: Flood safety: why shallow water kills · Hurricanes and storms now
- Your property's flood zone: FEMA Flood Map Service Center ↗ — this page cannot tell you that.
- Official preparedness guidance: Ready.gov ↗ and your county emergency management office.
What this page shows, and what it misses
FEMA's National Risk Index rates a whole county against every other US county; it is a planning-level estimate for nationwide comparison, not a flood-zone map and not a substitute for a local risk assessment or the risk to one home. Declarations are presidential disaster, emergency and fire management declarations that named this county; state declarations and SBA or USDA designations are not included. Tornadoes are counted when the county is one of up to four listed on the track; 670 tornadoes that crossed a state line carry no county list in NOAA's file and are left out. Connecticut now uses nine planning regions: older declarations and tornadoes listed by the eight former counties are assigned to every planning region that shares a town with that county, so a region can show events that hit only part of it.
Federal Emergency Management Agency (FEMA), National Risk Index Dataset: National Risk Index Counties - v1.20.0 (December 2025). Retrieved from https://services.arcgis.com/XG15cJAlne2vxtgt/ArcGIS/rest/services/National_Risk_Index_Counties/FeatureServer/0/query on November 2, 2026, 1:20 PM EST. This product uses the Federal Emergency Management Agency’s National Risk Index dataset API or downloadable datasets but is not endorsed by FEMA. The Federal Government or FEMA cannot vouch for the data or analyses derived from these data after the data have been retrieved from the Agency's website(s).
Federal Emergency Management Agency (FEMA), OpenFEMA Dataset: Disaster Declarations Summaries - v2, retrieved from https://www.fema.gov/api/open/v2/DisasterDeclarationsSummaries on November 2, 2026, 1:21 PM EST. This product uses the Federal Emergency Management Agency's OpenFEMA API, but is not endorsed by FEMA. The Federal Government or FEMA cannot vouch for the data or analyses derived from these data after the data have been retrieved from the Agency's website(s).
Tornado records: NOAA/NWS Storm Prediction Center, Severe Weather Database, tornadoes 1950–2025 (https://www.spc.noaa.gov/wcm/data/1950-2025_actual_tornadoes.csv, downloaded 2 November 2026). Public domain; not endorsed by NOAA. Compiled by Global Incident Tracker.
Questions about Lower Connecticut River Valley Planning Region
What natural disasters is Lower Connecticut River Valley Planning Region, Connecticut most at risk from?
Lower Connecticut River Valley Planning Region, Connecticut has a Relatively Moderate natural-hazard risk rating in FEMA's National Risk Index (v1.20, December 2025): a score of 83.8 out of 100, higher than about 83% of US counties, with inland (river and flash) flooding, hurricanes and coastal flooding scoring highest of its 18 hazards and $63 million a year in expected losses.
How many federal disaster declarations has Lower Connecticut River Valley Planning Region had?
OpenFEMA lists 31 federal disaster declarations that included Lower Connecticut River Valley Planning Region since 1978, not counting 2 for COVID-19; the latest is EM-3604-CT (Severe Storms, Flooding, and A Potential Dam Breach, declared 13 January 2024). Another 2 Connecticut declarations were made statewide without a county list.
How many tornadoes have hit Lower Connecticut River Valley Planning Region?
NOAA's Storm Prediction Center recorded 10 tornadoes touching Lower Connecticut River Valley Planning Region from 1950 to 2025. The deadliest: 21 Aug 1951, F3, 0.1 mi path, 0 killed, 8 injured (deaths and injuries are for the whole path).
Is the National Risk Index a flood zone map?
No. The National Risk Index is a planning-level estimate for a whole county, built for nationwide comparison. It does not tell you the flood zone or the risk of a single property: for that, look up the address on FEMA's Flood Map Service Center (msc.fema.gov) and ask your local floodplain manager.