Rockbridge weather by month
What a typical year looks like in Rockbridge, Illinois: average highs and lows, rain and snow, and the warmest and coldest days on record. Normals are the 1991–2020 averages at White Hall 1 E, 24 km from Rockbridge; records cover 1887–2026.
The year at a glance
- Precipitation a year
- 39.6 in1005 mm
- Snow a year
- 18 in46 cm
- Last spring freeze
- Apr 11
- First fall freeze
- Oct 17
- Heating degree days
- 5,479
- Cooling degree days
- 1,108
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 95°35° (cooling, 1%).
Month by month
Rockbridge in January
Highs average 35°2° and lows 18°−8°, with 2.1 in52 mm of precipitation and 6 in16 cm of snow in a typical January.
- Record high
- 77°25° (1909)
- Record low
- −26°−32° (1912)
- Heating degree days
- 1181
- Cooling degree days
- 0
Rockbridge in February
Highs average 41°5° and lows 22°−6°, with 2.1 in52 mm of precipitation and 5 in12 cm of snow in a typical February.
- Record high
- 83°28° (1932)
- Record low
- −25°−32° (1905)
- Heating degree days
- 946
- Cooling degree days
- 0
Rockbridge in March
Highs average 52°11° and lows 32°0°, with 2.9 in74 mm of precipitation and 1.8 in4.6 cm of snow in a typical March.
- Record high
- 94°34° (1907)
- Record low
- −13°−25° (1978)
- Heating degree days
- 727
- Cooling degree days
- 2
Rockbridge in April
Highs average 64°18° and lows 42°5°, with 4.4 in112 mm of precipitation and 0.4 in1 cm of snow in a typical April.
- Record high
- 93°34° (1930)
- Record low
- 11°−12° (1920)
- Heating degree days
- 374
- Cooling degree days
- 13
Rockbridge in May
Highs average 74°23° and lows 53°12°, with 4.8 in122 mm of precipitation in a typical May.
- Record high
- 103°39° (1934)
- Record low
- 22°−6° (1907)
- Heating degree days
- 131
- Cooling degree days
- 86
Rockbridge in June
Highs average 83°28° and lows 62°17°, with 4.7 in119 mm of precipitation in a typical June.
- Record high
- 106°41° (1934)
- Record low
- 35°2° (1946)
- Heating degree days
- 14
- Cooling degree days
- 236
Rockbridge in July
Highs average 86°30° and lows 66°19°, with 3.9 in98 mm of precipitation in a typical July.
- Record high
- 113°45° (1934)
- Record low
- 44°7° (1972)
- Heating degree days
- 2
- Cooling degree days
- 332
Rockbridge in August
Highs average 84°29° and lows 64°18°, with 3.4 in85 mm of precipitation in a typical August.
- Record high
- 112°44° (1934)
- Record low
- 41°5° (1910)
- Heating degree days
- 4
- Cooling degree days
- 283
Rockbridge in September
Highs average 79°26° and lows 55°13°, with 3 in76 mm of precipitation in a typical September.
- Record high
- 104°40° (1913)
- Record low
- 25°−4° (1942)
- Heating degree days
- 71
- Cooling degree days
- 131
Rockbridge in OctoberThis month
Highs average 67°19° and lows 43°6°, with 3 in77 mm of precipitation in a typical October.
- Record high
- 95°35° (1939)
- Record low
- 13°−11° (1925)
- Heating degree days
- 331
- Cooling degree days
- 24
Rockbridge in November
Highs average 52°11° and lows 33°0°, with 3.1 in79 mm of precipitation and 1.3 in3.3 cm of snow in a typical November.
- Record high
- 84°29° (1915)
- Record low
- −6°−21° (1929)
- Heating degree days
- 678
- Cooling degree days
- 1
Rockbridge in December
Highs average 41°5° and lows 24°−5°, with 2.3 in59 mm of precipitation and 4 in9 cm of snow in a typical December.
- Record high
- 74°23° (1948)
- Record low
- −20°−29° (1989)
- Heating degree days
- 1020
- Cooling degree days
- 0