Altona weather by month
What a typical year looks like in Altona, Illinois: average highs and lows, rain and snow, and the warmest and coldest days on record. Normals are the 1991–2020 averages at Galva, 13 km from Altona; records cover 1887–2026.
The year at a glance
- Precipitation a year
- 38.7 in982 mm
- Snow a year
- Rare
- Last spring freeze
- Apr 21
- First fall freeze
- Oct 11
- Heating degree days
- 6,468
- Cooling degree days
- 841
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 93°34° (cooling, 1%).
Month by month
Altona in January
Highs average 30°−1° and lows 13°−11°, with 1.6 in41 mm of precipitation in a typical January.
- Record high
- 67°19° (1909)
- Record low
- −32°−36° (2019)
- Heating degree days
- 1350
- Cooling degree days
- 0
Altona in February
Highs average 35°2° and lows 17°−8°, with 1.8 in45 mm of precipitation in a typical February.
- Record high
- 74°23° (2024)
- Record low
- −28°−33° (1905)
- Heating degree days
- 1093
- Cooling degree days
- 0
Altona in March
Highs average 48°9° and lows 27°−3°, with 2.4 in60 mm of precipitation in a typical March.
- Record high
- 86°30° (1910)
- Record low
- −12°−24° (1962)
- Heating degree days
- 848
- Cooling degree days
- 2
Altona in April
Highs average 61°16° and lows 38°3°, with 4.2 in107 mm of precipitation in a typical April.
- Record high
- 93°34° (1930)
- Record low
- 9°−13° (1920)
- Heating degree days
- 469
- Cooling degree days
- 7
Altona in May
Highs average 73°23° and lows 50°10°, with 4.8 in122 mm of precipitation in a typical May.
- Record high
- 105°41° (1934)
- Record low
- 22°−6° (2005)
- Heating degree days
- 177
- Cooling degree days
- 66
Altona in June
Highs average 82°28° and lows 60°15°, with 5.2 in131 mm of precipitation in a typical June.
- Record high
- 105°41° (1934)
- Record low
- 34°1° (1887)
- Heating degree days
- 23
- Cooling degree days
- 193
Altona in July
Highs average 84°29° and lows 63°17°, with 3.6 in92 mm of precipitation in a typical July.
- Record high
- 111°44° (1936)
- Record low
- 44°7° (1947)
- Heating degree days
- 5
- Cooling degree days
- 269
Altona in August
Highs average 82°28° and lows 60°16°, with 3.7 in95 mm of precipitation in a typical August.
- Record high
- 105°41° (1936)
- Record low
- 38°3° (1915)
- Heating degree days
- 13
- Cooling degree days
- 207
Altona in September
Highs average 77°25° and lows 52°11°, with 4 in101 mm of precipitation in a typical September.
- Record high
- 101°38° (1899)
- Record low
- 19°−7° (2003)
- Heating degree days
- 115
- Cooling degree days
- 85
Altona in OctoberThis month
Highs average 64°18° and lows 40°5°, with 2.8 in72 mm of precipitation in a typical October.
- Record high
- 93°34° (1897)
- Record low
- 9°−13° (1925)
- Heating degree days
- 413
- Cooling degree days
- 12
Altona in November
Highs average 48°9° and lows 29°−2°, with 2.6 in65 mm of precipitation in a typical November.
- Record high
- 83°28° (1950)
- Record low
- −7°−22° (1930)
- Heating degree days
- 792
- Cooling degree days
- 0
Altona in December
Highs average 36°2° and lows 19°−7°, with 2 in51 mm of precipitation in a typical December.
- Record high
- 70°21° (2021)
- Record low
- −26°−32° (1924)
- Heating degree days
- 1170
- Cooling degree days
- 0