South Beloit weather by month
What a typical year looks like in South Beloit, Illinois: average highs and lows, rain and snow, and the warmest and coldest days on record. Normals are the 1991–2020 averages at BELOIT, 2 km from South Beloit; records cover 1893–2026.
The year at a glance
- Precipitation a year
- 37.4 in950 mm
- Snow a year
- 36 in90 cm
- Last spring freeze
- Apr 22
- First fall freeze
- Oct 14
- Heating degree days
- 7,570
- Cooling degree days
- 468
Freeze dates are medians (half of years earlier, half later). Degree days use a 65°F base; HVAC design temperatures here are −8°−22° (heating, 99%) and 92°33° (cooling, 1%).
Month by month
South Beloit in January
Highs average 25°−4° and lows 11°−12°, with 1.6 in41 mm of precipitation and 10 in25 cm of snow in a typical January.
- Record high
- 61°16° (1944)
- Record low
- −29°−34° (2019)
- Heating degree days
- 1460
- Cooling degree days
- 0
South Beloit in February
Highs average 29°−1° and lows 14°−10°, with 1.5 in39 mm of precipitation and 7 in19 cm of snow in a typical February.
- Record high
- 74°23° (2024)
- Record low
- −28°−33° (2019)
- Heating degree days
- 1214
- Cooling degree days
- 0
South Beloit in March
Highs average 42°5° and lows 24°−5°, with 2.1 in54 mm of precipitation and 4 in11 cm of snow in a typical March.
- Record high
- 84°29° (1986)
- Record low
- −13°−25° (1962)
- Heating degree days
- 1003
- Cooling degree days
- 0
South Beloit in April
Highs average 55°13° and lows 34°1°, with 3.7 in94 mm of precipitation and 1.1 in2.8 cm of snow in a typical April.
- Record high
- 92°33° (1980)
- Record low
- 7°−14° (1982)
- Heating degree days
- 614
- Cooling degree days
- 2
South Beloit in May
Highs average 67°19° and lows 46°8°, with 4.3 in110 mm of precipitation in a typical May.
- Record high
- 103°39° (1934)
- Record low
- 26°−3° (1966)
- Heating degree days
- 302
- Cooling degree days
- 26
South Beloit in June
Highs average 76°24° and lows 56°13°, with 5.6 in143 mm of precipitation in a typical June.
- Record high
- 104°40° (1934)
- Record low
- 34°1° (1913)
- Heating degree days
- 71
- Cooling degree days
- 100
South Beloit in July
Highs average 80°26° and lows 60°15°, with 3.4 in85 mm of precipitation in a typical July.
- Record high
- 110°43° (1936)
- Record low
- 42°6° (1914)
- Heating degree days
- 19
- Cooling degree days
- 165
South Beloit in August
Highs average 78°26° and lows 58°15°, with 4.1 in105 mm of precipitation in a typical August.
- Record high
- 102°39° (1918)
- Record low
- 39°4° (1915)
- Heating degree days
- 30
- Cooling degree days
- 125
South Beloit in September
Highs average 71°22° and lows 50°10°, with 3.8 in97 mm of precipitation in a typical September.
- Record high
- 100°38° (1922)
- Record low
- 23°−5° (1899)
- Heating degree days
- 172
- Cooling degree days
- 46
South Beloit in OctoberThis month
Highs average 58°15° and lows 39°4°, with 2.8 in70 mm of precipitation and 0.2 in0.5 cm of snow in a typical October.
- Record high
- 89°32° (1963)
- Record low
- 4°−16° (1925)
- Heating degree days
- 515
- Cooling degree days
- 4
South Beloit in November
Highs average 43°6° and lows 27°−3°, with 2.4 in61 mm of precipitation and 2.7 in6.9 cm of snow in a typical November.
- Record high
- 78°26° (1933)
- Record low
- −12°−24° (1947)
- Heating degree days
- 891
- Cooling degree days
- 0
South Beloit in December
Highs average 31°−1° and lows 17°−8°, with 2 in50 mm of precipitation and 10 in26 cm of snow in a typical December.
- Record high
- 67°19° (2021)
- Record low
- −25°−32° (1903)
- Heating degree days
- 1279
- Cooling degree days
- 0