Hurricanes and Tornadoes That Hit Chelsea, MA

The nearest NOAA station with 1991–2020 climate normals is Boston Logan International Airport, MA, 3 miles southeast of Chelsea at 12 feet. July is the warmest, with an average high of 82°F and low of 66°F; January is the coolest, at 37°F and 23°F. December is the wettest at 4.3 inches of precipitation on average and February and August the driest at 3.2 inches; the year adds up to 43.7 inches over 77 days with at least a tenth of an inch. June to November, the hurricane season months, bring 50% of the year's precipitation (21.7 of 43.7 inches). September has brought the most of the 47 tropical systems that passed within 75 miles (18); a normal September there has highs of 73°F and 3.6 inches of precipitation. Highs reach 90°F on about 14 days a year, almost all from June to August. Lows fall below freezing on about 92 nights a year. Snowfall averages 49.2 inches a year, most of it in February. That 43.7 inches is more than at 8 of the 65 Massachusetts stations used on this site (12%). Cambridge, 4 miles west, has its own station (Jamaica Plain, MA): 49.4 inches a year, 5.7 more than here, and a July average high of 85°F against 82°F.

Sea level at the Boston tide gauge, 3 miles from Chelsea, has risen 1.17 ± 0.03 inches per decade from 1921 to 2025, NOAA's linear trend; at that pace it is 11.7 inches in a hundred years. That is faster than at 68 of the 144 U.S. gauges with a NOAA trend.

Since 1996, the National Weather Service has logged 514 flood, rain, thunderstorm wind and lightning events that began within 10 miles of Chelsea: 309 thunderstorm wind reports, 123 floods, 53 flash floods and 29 lightning strikes. They killed 1 person and injured 23, and the NWS estimated $40.9 million in property and crop damage. The strongest thunderstorm gust on record here was 81 mph, on July 18, 2012. July has had the most flash floods, 33 of 53. Of the 339 Massachusetts cities on this site with a flash flood on record, 307 have had fewer than Chelsea.

Flood insurance policyholders in Chelsea's ZIP code 02150 have filed 39 claims with the National Flood Insurance Program since 1978, and were paid $169,000 for buildings and contents, in the dollars of each year. The most came from Flooding in 1998: 12 claims (31% of all) and $38,000. 46% of the claims carry the name of a storm or flood event; the rest have no event name. Of the 229 Massachusetts cities on this site with 10 or more claims, 114 have fewer than Chelsea.