Colchester weather by month
What a typical year looks like in Colchester, Connecticut: average highs and lows, rain and snow, and the warmest and coldest days on record. Normals are the 1991–2020 averages at NORWICH PUBLIC UTILITY PLANT, 23 km from Colchester; records cover 1956–2026.
The year at a glance
- Precipitation a year
- 52.2 in1325 mm
- Snow a year
- 28 in71 cm
- Last spring freeze
- Apr 17
- First fall freeze
- Oct 19
- Heating degree days
- 5,580
- Cooling degree days
- 802
Freeze dates are medians (half of years earlier, half later). Degree days use a 65°F base; HVAC design temperatures here are 4°−16° (heating, 99%) and 94°34° (cooling, 1%).
Month by month
Colchester in January
Highs average 38°3° and lows 21°−6°, with 3.9 in99 mm of precipitation and 9 in23 cm of snow in a typical January.
- Record high
- 70°21° (2020)
- Record low
- −21°−29° (1994)
- Heating degree days
- 1102
- Cooling degree days
- 0
Colchester in February
Highs average 41°5° and lows 23°−5°, with 3.8 in95 mm of precipitation and 7 in18 cm of snow in a typical February.
- Record high
- 72°22° (1981)
- Record low
- −17°−27° (1996)
- Heating degree days
- 932
- Cooling degree days
- 0
Colchester in March
Highs average 48°9° and lows 29°−1°, with 5.1 in129 mm of precipitation and 5 in13 cm of snow in a typical March.
- Record high
- 85°29° (1998)
- Record low
- −1°−18° (1962)
- Heating degree days
- 818
- Cooling degree days
- 0
Colchester in April
Highs average 59°15° and lows 39°4°, with 4.7 in120 mm of precipitation and 0.8 in2 cm of snow in a typical April.
- Record high
- 94°34° (2002)
- Record low
- 17°−8° (1964)
- Heating degree days
- 477
- Cooling degree days
- 3
Colchester in May
Highs average 70°21° and lows 49°9°, with 3.6 in92 mm of precipitation in a typical May.
- Record high
- 98°37° (1996)
- Record low
- 27°−3° (1985)
- Heating degree days
- 203
- Cooling degree days
- 29
Colchester in June
Highs average 78°26° and lows 59°15°, with 4.3 in108 mm of precipitation in a typical June.
- Record high
- 101°38° (2025)
- Record low
- 33°1° (1983)
- Heating degree days
- 34
- Cooling degree days
- 138
Colchester in July
Highs average 84°29° and lows 65°18°, with 3.6 in92 mm of precipitation in a typical July.
- Record high
- 101°38° (1991)
- Record low
- 43°6° (1988)
- Heating degree days
- 2
- Cooling degree days
- 294
Colchester in August
Highs average 83°28° and lows 63°17°, with 4.4 in112 mm of precipitation in a typical August.
- Record high
- 102°39° (2001)
- Record low
- 40°4° (1957)
- Heating degree days
- 4
- Cooling degree days
- 242
Colchester in September
Highs average 76°24° and lows 55°13°, with 4.8 in122 mm of precipitation in a typical September.
- Record high
- 97°36° (1983)
- Record low
- 29°−2° (1957)
- Heating degree days
- 82
- Cooling degree days
- 87
Colchester in OctoberThis month
Highs average 64°18° and lows 44°6°, with 4.9 in123 mm of precipitation in a typical October.
- Record high
- 88°31° (1956)
- Record low
- 18°−8° (1980)
- Heating degree days
- 358
- Cooling degree days
- 9
Colchester in November
Highs average 53°12° and lows 34°1°, with 4.2 in106 mm of precipitation and 0.3 in0.8 cm of snow in a typical November.
- Record high
- 80°27° (2022)
- Record low
- 6°−14° (1989)
- Heating degree days
- 641
- Cooling degree days
- 0
Colchester in December
Highs average 43°6° and lows 27°−3°, with 5 in126 mm of precipitation and 6 in14 cm of snow in a typical December.
- Record high
- 77°25° (1998)
- Record low
- −13°−25° (1980)
- Heating degree days
- 927
- Cooling degree days
- 0