Hurricanes and Tornadoes That Hit Haddam, CT

The nearest NOAA station with 1991–2020 climate normals is Meriden Markham Municipal Airport, CT, 17 miles west of Haddam at 103 feet. July is the warmest, with an average high of 84°F and low of 63°F; January is the coolest, at 37°F and 19°F. October is the wettest at 4.5 inches of precipitation on average and February the driest at 2.9 inches; the year adds up to 45.0 inches over 74 days with at least a tenth of an inch. June to November, the hurricane season months, bring 52% of the year's precipitation (23.2 of 45.0 inches); the other six months are drier. September has brought the most of the 54 tropical systems that passed within 75 miles (22); a normal September there has highs of 75°F and 4.3 inches of precipitation. Highs reach 90°F on about 15 days a year, almost all from June to September. Lows fall below freezing on about 129 nights a year. That 45.0 inches is more than at 6 of the 27 Connecticut stations used on this site (22%). Moodus, 5 miles northeast, has its own station (Hartford Brainard Field, CT): 42.9 inches a year, 2.1 less than here, and a July average high of 85°F against 84°F.

Water temperature at the NOAA tide station New London, CT, 22 miles east, 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, 22 miles from Haddam, 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 76 flood, rain, thunderstorm wind and lightning events that began within 10 miles of Haddam: 61 thunderstorm wind reports, 8 flash floods, 4 lightning strikes and 3 floods. They killed 0 people and injured 1, and the NWS estimated $325,000 in property and crop damage. The strongest thunderstorm gust on record here was 110 mph, on July 21, 2010. September has had the most flash floods, 4 of 8. Of the 186 Connecticut cities on this site with a flash flood on record, 27 have had fewer than Haddam.

Flood insurance policyholders in Haddam's ZIP code 06438 have filed 38 claims with the National Flood Insurance Program since 1981, and were paid $276,000 for buildings and contents, in the dollars of each year. The most came from Flooding in 1987: 15 claims (39% of all) and $116,000. 63% 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, 50 have fewer than Haddam.