Hurricanes and Tornadoes That Hit Seymour, CT

The nearest NOAA station with 1991–2020 climate normals is Mt Carmel, CT, 9 miles east of Seymour at 180 feet. July is the warmest, with an average high of 85°F and low of 64°F; January is the coolest, at 38°F and 20°F. June and October are the wettest at 4.9 inches of precipitation on average and February the driest at 3.5 inches; the year adds up to 50.5 inches over 82 days with at least a tenth of an inch. June to November, the hurricane season months, bring 52% of the year's precipitation (26.1 of 50.5 inches); the other six months are drier. September has brought the most of the 49 tropical systems that passed within 75 miles (22); a normal September there has highs of 76°F and 4.3 inches of precipitation. Highs reach 90°F on about 14 days a year, almost all from May to September. Lows fall below freezing on about 123 nights a year. That 50.5 inches is more than at 15 of the 27 Connecticut stations used on this site (56%). Derby, 4 miles south, has its own station (New Haven Tweed Airport, CT): 41.8 inches a year, 8.7 less than here, and a July average high of 82°F against 85°F.

Water temperature at the NOAA tide station New Haven, CT, 11 miles southeast, averaged 75°F in August and 37°F in February over 2021–2025. No month averaged 80°F. Sea level at the Bridgeport tide gauge, 16 miles from Seymour, has risen 1.35 ± 0.08 inches per decade from 1964 to 2025, NOAA's linear trend; at that pace it is 13.5 inches in a hundred years. That is faster than at 81 of the 144 U.S. gauges with a NOAA trend.

Since 1996, the National Weather Service has logged 239 flood, rain, thunderstorm wind and lightning events that began within 10 miles of Seymour: 164 thunderstorm wind reports, 62 flash floods, 8 floods and 5 lightning strikes. They killed 3 people and injured 7, and the NWS estimated $2.3 million in property and crop damage. The strongest thunderstorm gust on record here was 96 mph, on July 31, 2009. August has had the most flash floods, 32 of 62. Of the 186 Connecticut cities on this site with a flash flood on record, 174 have had fewer than Seymour.

Flood insurance policyholders in Seymour's ZIP code 06483 have filed 44 claims with the National Flood Insurance Program since 1978, and were paid $1.9 million for buildings and contents, in the dollars of each year. 27% 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, 56 have fewer than Seymour.