Connecticut landslide risk

9 counties scored 0 rated Very High

Western Connecticut Planning Region has the highest landslide risk in Connecticut, scoring 89 out of 100 — rated "Relatively Moderate" by FEMA's National Risk Index.

# County NRI score Rating NOAA events
2016–2026
1 Western Connecticut Planning Region 89 Relatively Moderate 0
2 Capitol Planning Region 87.2 Relatively Moderate 0
3 Naugatuck Valley Planning Region 86.8 Relatively Low 0
4 Northwest Hills Planning Region 82.8 Relatively Low 0
5 Southeastern Connecticut Planning Region 76.7 Relatively Low 0
6 Lower Connecticut River Valley Planning Region 72.5 Relatively Low 0
7 South Central Connecticut Planning Region 69.2 Relatively Low 0
8 Northeastern Connecticut Planning Region 62.2 Very Low 0
9 Greater Bridgeport Planning Region 46.5 Very Low 0

Source: FEMA National Risk Index v1.20.0, December 2025. Scores are 0–100 percentile rankings among all US counties. See the methodology page for definitions. Download the full CSV for all counties.

Landslide risk nationally:

Other hazard risks in Connecticut:

Frequently asked questions

What is the highest landslide risk county in Connecticut?

Western Connecticut Planning Region, CT has the highest landslide risk in Connecticut, with a FEMA National Risk Index score of 89 out of 100 (rated "Relatively Moderate").

What causes landslide risk in Connecticut?

Landslide risk covers expected losses from hillslope failures, rockfalls, and debris flows triggered by heavy rainfall, snowmelt, wildfire, or earthquakes. High scores concentrate in the Pacific Northwest, California coastal ranges, Appalachians, and Rocky Mountain foothills, where steep terrain combines with intense precipitation or seismic activity.