Hurricanes and Tornadoes That Hit Dorchester, MA

The nearest NOAA station with 1991–2020 climate normals is Jamaica Plain, MA, 3 miles west of Dorchester at 95 feet. July is the warmest, with an average high of 85°F and low of 64°F; January is the coolest, at 37°F and 19°F. December is the wettest at 5.1 inches of precipitation on average and July the driest at 3.5 inches; the year adds up to 49.4 inches. June to November, the hurricane season months, bring 49% of the year's precipitation (24.4 of 49.4 inches); the other six months are wetter. September has brought the most of the 48 tropical systems that passed within 75 miles (18); a normal September there has highs of 76°F and 4.0 inches of precipitation. Highs reach 90°F on about 20 days a year, almost all from May to September. Lows fall below freezing on about 121 nights a year. That 49.4 inches is more than at 42 of the 65 Massachusetts stations used on this site (65%). South Boston, 3 miles northeast, has its own station (Boston Logan International Airport, MA): 43.7 inches a year, 5.7 less than here, and a July average high of 82°F against 85°F.

Sea level at the Boston tide gauge, 4 miles from Dorchester, 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 543 flood, rain, thunderstorm wind and lightning events that began within 10 miles of Dorchester: 320 thunderstorm wind reports, 132 floods, 59 flash floods and 32 lightning strikes. They killed 2 people and injured 28, and the NWS estimated $32.2 million in property and crop damage. The strongest thunderstorm gust on record here was 104 mph, on June 22, 1997. July has had the most flash floods, 40 of 59. Of the 339 Massachusetts cities on this site with a flash flood on record, 328 have had fewer than Dorchester.

Flood insurance policyholders in Dorchester's 4 ZIP codes have filed 51 claims with the National Flood Insurance Program since 1978, and were paid $1.4 million for buildings and contents, in the dollars of each year. The most came from Flooding in 1978: 17 claims (33% of all) and $204,000. 69% 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, 130 have fewer than Dorchester.