Weather & Climate in Thomaston, CT
Temperature, precipitation, air quality, natural hazards, and monthly weather data.
Thomaston experiences four distinct seasons with an average annual temperature of 50°F (10°C). Winters average 27°F in January while summers reach 73°F in July. Annual precipitation totals 52.0 inches (wetter than the 38-inch national average). The area receives 38.6 inches of snow annually, a moderate snowfall amount. The city sits at an elevation of 641 feet.
Temperature
27°F Jan (-3°C)
73°F Jul (23°C)
| Annual Average | 50.0°F |
| 7% below US avg | |
| January Average | 27°F (-3°C) |
| July Average | 73°F (23°C) |
Geography
| Elevation | 641 ft (195 m) |
| Area | 1.0 sq mi (2.7 km²) |
| Population Density | 1,728/sq mi |
| Coordinates | 41.6768°N, 73.0830°W |
| Timezone | America/New_York |
| County | Naugatuck Valley Planning Region County |
| Nearest Airport | Bradley International (BDL) 27 miles away |
Precipitation & Snow
Air Quality
Natural Hazard Risk
| Overall Risk | Relatively Moderate |
| Risk Score | 93.2 / 100 |
| Social Vulnerability | 35.7 / 100 |
| Community Resilience | 77.2 / 100 |
Hazard Breakdown
| Tornado | Relatively Moderate |
| Hurricane | Relatively High |
| Earthquake | Relatively Low |
| Wildfire | Very Low |
| Flood | Relatively High |
| Hail | Relatively Low |
| Strong Wind | Relatively High |
| Heat Wave | Relatively Moderate |
| Winter Weather | Relatively High |
| Lightning | Relatively High |
| Ice Storm | Relatively High |
| Drought | Relatively Low |
| Cold Wave | Relatively Moderate |
| Landslide | Relatively Low |
| Coastal Flood | Very Low |
Source: FEMA National Risk Index v1.20 (Dec 2025)
Earthquake History
26 earthquakes (M2.5+) recorded within 150 km since 1990. Strongest on record: M3.7.
| Oct 2, 1994 | 6 km W of Hardwick, Massachusetts | M3.7 | 100 km | 10 km |
| Jan 12, 2015 | 0 km NE of Wauregan, Connecticut | M3.3 | 98 km | 5 km |
| Jun 16, 2000 | 5 km NE of Granville, Massachusetts | M3.3 | 52 km | 10 km |
| Oct 2, 1994 | 1 km NW of Hardwick, Massachusetts | M3.3 | 104 km | 10 km |
| Dec 13, 2009 | 15 km N of Medusa, New York | M3.2 | 131 km | 10 km |
| May 18, 2009 | 15 km N of Medusa, New York | M3.1 | 131 km | 9 km |
| Jul 24, 2007 | 12 km SSW of Altamont, New York | M3.1 | 134 km | 15 km |
| Aug 3, 2025 | 0 km W of Little Ferry, New Jersey | M3.0 | 122 km | 10 km |
| Oct 28, 1991 | 3 km WNW of Stamford, Connecticut | M3.0 | 79 km | 10 km |
| Oct 21, 2009 | 15 km N of Medusa, New York | M2.9 | 130 km | 7 km |
| Aug 5, 2025 | 1 km N of Hillsdale, New Jersey | M2.8 | 109 km | 12 km |
| Mar 10, 1992 | 2 km SW of Napeague, New York | M2.8 | 113 km | 10 km |
| Aug 27, 2011 | 5 km WSW of Altamont, New York | M2.8 | 139 km | 22 km |
| Mar 22, 2009 | 9 km SW of Altamont, New York | M2.8 | 136 km | 16 km |
| Apr 12, 1991 | 2 km ENE of North Castle, New York | M2.7 | 75 km | 9 km |
| Aug 25, 2011 | 5 km WSW of Altamont, New York | M2.7 | 139 km | 18 km |
| Feb 18, 2009 | 15 km N of Medusa, New York | M2.7 | 130 km | 9 km |
| Feb 20, 2009 | 15 km SSW of Altamont, New York | M2.7 | 130 km | 8 km |
| Aug 14, 2014 | 6 km SW of Deep River Center, Connecticut | M2.7 | 61 km | 4 km |
| Oct 27, 2001 | 1 km NNW of Manhattan, New York | M2.6 | 123 km | 5 km |
Source: USGS Earthquake Catalog (M2.5+, 1990-2025). Sorted by magnitude.
Hurricane History
2 hurricanes (Category 1+) recorded within 500 km since 1980. Strongest on record: Category 2.
| Year | Name | Category | Max Wind | Closest |
| 1991 | Bob | Category 2 | 104 mph | 135 km |
| 1985 | Gloria | Category 1 | 86 mph | 34 km |
Source: NOAA IBTrACS (Category 1+, 1980-2026).
Tornado History
244 tornadoes (EF0+) recorded within 100 km since 1950. Strongest on record: EF4. Total: 16 fatalities, 997 injuries.
| Date | Rating | Distance | Path | Fatalities |
| May 29, 1995 | EF4 | 65 km | 11.5 mi | 3 |
| Jul 10, 1989 | EF4 | 36 km | 3.0 mi | 0 |
| Oct 3, 1979 | EF4 | 41 km | 11.3 mi | 3 |
| Aug 28, 1973 | EF4 | 87 km | 9.8 mi | 4 |
| Jun 1, 2011 | EF3 | 55 km | 37.6 mi | 3 |
| Jun 16, 1974 | EF3 | 89 km | 49.1 mi | 0 |
| Sep 13, 1971 | EF3 | 80 km | 0.5 mi | 0 |
| Jul 29, 1971 | EF3 | 14 km | 0.1 mi | 0 |
| May 24, 1962 | EF3 | 14 km | 11.6 mi | 1 |
| May 10, 1954 | EF3 | 58 km | 0.3 mi | 0 |
| Aug 21, 1951 | EF3 | 50 km | 0.1 mi | 0 |
| May 15, 2018 | EF2 | 54 km | 1.2 mi | 0 |
| Jul 12, 2006 | EF2 | 94 km | 10.1 mi | 0 |
| Jul 21, 2003 | EF2 | 95 km | 1.3 mi | 0 |
| Jul 21, 2003 | EF2 | 94 km | 1.5 mi | 0 |
| Jun 23, 2001 | EF2 | 14 km | 0.5 mi | 0 |
| May 18, 2000 | EF2 | 75 km | 0.2 mi | 0 |
| Aug 8, 1999 | EF2 | 89 km | 4.0 mi | 0 |
| Jul 3, 1997 | EF2 | 56 km | 4.5 mi | 0 |
| Jul 3, 1997 | EF2 | 56 km | 3.7 mi | 0 |
Source: NOAA Storm Prediction Center (EF0+, 1950-2024, US only).
Tsunami History
1 tsunami recorded within 500 km. Highest wave on record: 0.3 m (1 ft).
| Year | Location | Cause | Max Wave | Deaths | Distance |
| 1964 | LONG ISLAND, NY | Meteorological | 0.3 m | - | 98 km |
Source: NOAA/NCEI Historical Tsunami Database.
Wildfire History
3 wildfires (100+ acres) recorded within 100 km. Largest: UNNAMED (2,224 acres, 2008).
| Year | Name | Acres Burned | Distance |
| 2008 | UNNAMED | 2,224 | 99 km |
| 2012 | CRESCENT BOW FIRE | 1,068 | 91 km |
| 1988 | UNNAMED | 833 | 100 km |
Source: NIFC/IRWIN Wildfire Records (100+ acres).
Monthly Weather
| Month | Avg Temperature | Precipitation | Summary |
|---|---|---|---|
| January | 27°F (-3°C) | 3.4 in | Coldest |
| February | 29°F (-2°C) | 3.2 in | Driest |
| March | 36°F (2°C) | 4.2 in | |
| April | 48°F (9°C) | 4.5 in | |
| May | 59°F (15°C) | 4.3 in | |
| June | 68°F (20°C) | 4.5 in | |
| July | 73°F (23°C) | 4.7 in | Warmest |
| August | 71°F (22°C) | 4.4 in | |
| September | 64°F (18°C) | 4.6 in | |
| October | 52°F (11°C) | 5.4 in | Wettest |
| November | 42°F (6°C) | 4.0 in | |
| December | 33°F (0°C) | 4.7 in |
Thomaston has a seasonal temperature swing of 46°F / from 27°F in January to 73°F in July. Total annual precipitation is 52.0 inches, with October being the wettest month (5.4") and February the driest (3.2").