Connecticut tornado risk

9 counties scored 0 rated Very High

Capitol Planning Region has the highest tornado risk in Connecticut, scoring 90.5 out of 100 — rated "Relatively High" by FEMA's National Risk Index.

# County NRI score Rating NOAA events
2016–2026
1 Capitol Planning Region 90.5 Relatively High 0
2 South Central Connecticut Planning Region 78 Relatively Moderate 0
3 Naugatuck Valley Planning Region 73.1 Relatively Moderate 0
4 Western Connecticut Planning Region 69.2 Relatively Moderate 0
5 Southeastern Connecticut Planning Region 53.1 Relatively Low 0
6 Lower Connecticut River Valley Planning Region 43.3 Relatively Low 0
7 Northwest Hills Planning Region 42.9 Relatively Low 0
8 Greater Bridgeport Planning Region 41.7 Relatively Low 0
9 Northeastern Connecticut Planning Region 28.3 Relatively 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.

Tornado risk nationally:

Other hazard risks in Connecticut:

Frequently asked questions

What is the highest tornado risk county in Connecticut?

Capitol Planning Region, CT has the highest tornado risk in Connecticut, with a FEMA National Risk Index score of 90.5 out of 100 (rated "Relatively High").

What causes tornado risk in Connecticut?

Tornado risk concentrates in the central and southern plains ("Tornado Alley") and the Southeast ("Dixie Alley"), where atmospheric conditions favor supercell thunderstorm development. The highest scores often belong to counties with significant mobile home and manufactured housing stock, which carries disproportionate tornado mortality risk.