Boston weather by month
What a typical year looks like in Boston, Indiana: average highs and lows, rain and snow, and the warmest and coldest days on record. Normals are the 1991–2020 averages at Eaton, 19 km from Boston; records cover 1956–2026.
The year at a glance
- Precipitation a year
- 43.1 in1095 mm
- Snow a year
- Rare
- Last spring freeze
- Apr 25
- First fall freeze
- Oct 18
- Heating degree days
- 5,824
- Cooling degree days
- 834
Freeze dates are medians (half of years earlier, half later). Degree days use a 65°F base; HVAC design temperatures here are −2°−19° (heating, 99%) and 93°34° (cooling, 1%).
Month by month
Boston in January
Highs average 35°2° and lows 17°−8°, with 3.1 in80 mm of precipitation in a typical January.
- Record high
- 68°20° (1967)
- Record low
- −33°−36° (1994)
- Heating degree days
- 1196
- Cooling degree days
- 0
Boston in February
Highs average 40°4° and lows 19°−7°, with 2.6 in65 mm of precipitation in a typical February.
- Record high
- 75°24° (2018)
- Record low
- −20°−29° (1985)
- Heating degree days
- 995
- Cooling degree days
- 0
Boston in March
Highs average 50°10° and lows 28°−2°, with 3.6 in91 mm of precipitation in a typical March.
- Record high
- 85°29° (2026)
- Record low
- −11°−24° (1978)
- Heating degree days
- 800
- Cooling degree days
- 1
Boston in April
Highs average 63°17° and lows 38°3°, with 4.5 in115 mm of precipitation in a typical April.
- Record high
- 87°31° (1960)
- Record low
- 14°−10° (1982)
- Heating degree days
- 435
- Cooling degree days
- 6
Boston in May
Highs average 73°23° and lows 49°10°, with 4.8 in122 mm of precipitation in a typical May.
- Record high
- 96°36° (1962)
- Record low
- 25°−4° (1966)
- Heating degree days
- 174
- Cooling degree days
- 57
Boston in June
Highs average 82°28° and lows 59°15°, with 4.6 in118 mm of precipitation in a typical June.
- Record high
- 102°39° (2012)
- Record low
- 27°−3° (1984)
- Heating degree days
- 24
- Cooling degree days
- 178
Boston in July
Highs average 85°29° and lows 62°17°, with 4.3 in109 mm of precipitation in a typical July.
- Record high
- 102°39° (1988)
- Record low
- 42°6° (1979)
- Heating degree days
- 3
- Cooling degree days
- 262
Boston in August
Highs average 84°29° and lows 60°15°, with 3 in76 mm of precipitation in a typical August.
- Record high
- 101°38° (1988)
- Record low
- 38°3° (1981)
- Heating degree days
- 6
- Cooling degree days
- 220
Boston in September
Highs average 79°26° and lows 53°11°, with 3 in77 mm of precipitation in a typical September.
- Record high
- 98°37° (1964)
- Record low
- 20°−7° (1983)
- Heating degree days
- 82
- Cooling degree days
- 99
Boston in OctoberThis month
Highs average 66°19° and lows 41°5°, with 3.2 in81 mm of precipitation in a typical October.
- Record high
- 91°33° (2019)
- Record low
- 12°−11° (1976)
- Heating degree days
- 369
- Cooling degree days
- 11
Boston in November
Highs average 52°11° and lows 31°−1°, with 3.2 in80 mm of precipitation in a typical November.
- Record high
- 80°27° (2016)
- Record low
- −3°−19° (1976)
- Heating degree days
- 708
- Cooling degree days
- 0
Boston in December
Highs average 41°5° and lows 23°−5°, with 3.2 in81 mm of precipitation in a typical December.
- Record high
- 72°22° (1982)
- Record low
- −30°−34° (1983)
- Heating degree days
- 1032
- Cooling degree days
- 0