Chelmsford, MA Tornado History — 54 Tornadoes Since 1950
How many tornadoes has Chelmsford, MA had?
Chelmsford has had 54 tornadoes on record within 25 miles since 1950, including 3 violent (EF3+) tornadoes.
When was the most recent tornado near Chelmsford?
The most recent tornado within 25 miles of Chelmsford was an EF0 on September 6, 2025.
When is tornado season in Chelmsford?
July is historically the peak month for tornadoes near Chelmsford, with 21 on record. Spring through early summer (April–June) generally sees the highest activity across most of the central and southern United States.
At a Glance
Recent Tornado Activity Near Chelmsford
The last 20 years of confirmed tornadoes within 25 miles — 8 total, averaging 0.4 per year over this window.
Tornadoes by Decade
Tornadoes by Enhanced Fujita Rating
F0–F5 ratings (pre-2007) are grouped with their EF equivalents. The Enhanced Fujita scale replaced the original Fujita scale in February 2007.
Tornadoes by Month
Casualties on Record Near Chelmsford
96 fatalities have been recorded within 25 miles of Chelmsford since 1950, across 3 events. 1,260 injuries have been reported across all events. 1953 was the deadliest year on record.
The deadliest single event was a F4 on June 9, 1953, which caused 94 fatalities along a 34.9-mile track.
Notable Tornadoes Near Chelmsford
About Tornadoes in Chelmsford
This overview was written July 24, 2026. The tornado counts and notable-event figures elsewhere on this page reflect the latest data and may differ from this summary.
Chelmsford lies in northeastern Massachusetts, in the wooded country of the Merrimack Valley northwest of Boston. Southern New England is not a major tornado region, but it records tornadoes in most years, and this inland part of the state has experienced them during the warm season.
These tornadoes are largely a summertime concern. When humid air over the region becomes unstable under strong heating and a passing disturbance aloft supplies wind shear, thunderstorms can grow tall and occasionally rotate. The inland setting lets heat and humidity build on hot afternoons, away from the coast's moderating sea breeze. Because such storms are infrequent, they can arrive with little public expectation.
Tornado intensity is rated on the Enhanced Fujita (EF) scale, which runs from EF0 to EF5 according to surveyed damage rather than a measured wind speed. The vast majority of the region's tornadoes are weak, with strong ones rare. The tornado history for the Chelmsford area — counts, the decade and rating breakdowns, and the deadliest, costliest, and most recent events — is compiled from the NOAA Storm Prediction Center and shown in the figures elsewhere on this page.