Hurricanes and Tornadoes That Hit Stonington, CT

The nearest NOAA station with 1991–2020 climate normals is Westerly State Airport, RI, 6 miles east of Stonington at 81 feet. July is the warmest, with an average high of 82°F and low of 66°F; January is the coolest, at 40°F and 25°F. October is the wettest at 4.3 inches of precipitation on average and February the driest at 2.8 inches; the year adds up to 42.9 inches over 73 days with at least a tenth of an inch. June to November, the hurricane season months, bring 50% of the year's precipitation (21.6 of 42.9 inches). September has brought the most of the 58 tropical systems that passed within 75 miles (23); a normal September there has highs of 74°F and 3.8 inches of precipitation. Highs reach 90°F on about 3 days a year, almost all from July. Lows fall below freezing on about 109 nights a year. That 42.9 inches is more than at 3 of the 27 Connecticut stations used on this site (11%). Mystic, 3 miles west, has its own station (Groton, CT): 48.9 inches a year, 6.0 more than here, and a July average high of 81°F against 82°F.

Water temperature at the NOAA tide station New London, CT, 10 miles west, averaged 71°F in August and 39°F in February over 2021–2025. No month averaged 80°F. Sea level at the New London tide gauge, 10 miles from Stonington, has risen 1.16 ± 0.04 inches per decade from 1938 to 2025, NOAA's linear trend; at that pace it is 11.6 inches in a hundred years. That is faster than at 66 of the 144 U.S. gauges with a NOAA trend.

Since 1996, the National Weather Service has logged 89 flood, rain, thunderstorm wind and lightning events that began within 10 miles of Stonington: 37 flash floods, 32 thunderstorm wind reports, 15 floods, 4 lightning strikes and 1 heavy rain event. They killed 2 people and injured 14, and the NWS estimated $6.0 million in property and crop damage. The strongest thunderstorm gust on record here was 70 mph, on June 24, 2008. July has had the most flash floods, 18 of 37. Of the 186 Connecticut cities on this site with a flash flood on record, 113 have had fewer than Stonington.

Flood insurance policyholders in Stonington's ZIP code 06378 have filed 164 claims with the National Flood Insurance Program since 1978, and were paid $2.3 million for buildings and contents, in the dollars of each year. The most came from Hurricane Sandy in 2012: 71 claims (43% of all) and $1.5 million, then March 2010 Nor'easter in 2010 with 22. 68% of the claims carry the name of a storm or flood event; the rest have no event name. Of the 128 Connecticut cities on this site with 10 or more claims, 94 have fewer than Stonington.