Hurricanes and Tornadoes That Hit Cos Cob, CT

The nearest NOAA station with 1991–2020 climate normals is Stamford 5 N, CT, 6 miles northeast of Cos Cob at 190 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 22°F. September is the wettest at 5.2 inches of precipitation on average and February the driest at 3.1 inches; the year adds up to 51.5 inches over 81 days with at least a tenth of an inch. June to November, the hurricane season months, bring 51% of the year's precipitation (26.5 of 51.5 inches); the other six months are drier. September has brought the most of the 48 tropical systems that passed within 75 miles (21); a normal September there has highs of 76°F and 5.2 inches of precipitation. Highs reach 90°F on about 18 days a year, almost all from May to September. Lows fall below freezing on about 119 nights a year. Snowfall averages 34.0 inches a year, most of it in February. That 51.5 inches is more than at 19 of the 27 Connecticut stations used on this site (70%). Greenwich, 2 miles west, has its own station (Westchester Co Airport, NY): 47.7 inches a year, 3.8 less than here, and a July average high of 83°F against 85°F.

Water temperature at the NOAA tide station Kings Point, NY, 19 miles southwest, averaged 74°F in August and 38°F in February over 2021–2025. No month averaged 80°F. Sea level at the Kings Point tide gauge, 19 miles from Cos Cob, has risen 1.08 ± 0.04 inches per decade from 1931 to 2025, NOAA's linear trend; at that pace it is 10.8 inches in a hundred years. That is faster than at 62 of the 144 U.S. gauges with a NOAA trend.

Since 1996, the National Weather Service has logged 220 flood, rain, thunderstorm wind and lightning events that began within 10 miles of Cos Cob: 127 thunderstorm wind reports, 74 flash floods, 11 floods, 6 lightning strikes and 2 heavy rain events. They killed 5 people and injured 5, and the NWS estimated $14.8 million in property and crop damage. The strongest thunderstorm gust on record here was 81 mph, on July 21, 2010. July has had the most flash floods, 27 of 74. Of the 186 Connecticut cities on this site with a flash flood on record, 180 have had fewer than Cos Cob.

Flood insurance policyholders in Cos Cob's ZIP code 06807 have filed 124 claims with the National Flood Insurance Program since 1978, and were paid $2.1 million for buildings and contents, in the dollars of each year. The most came from Hurricane Sandy in 2012: 24 claims (19% of all) and $472,000, then Hurricane Ida in 2021 with 22. The year with the most claims was 2007, with 31. 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, 86 have fewer than Cos Cob.