Allerton weather by month
What a typical year looks like in Allerton, Iowa: average highs and lows, rain and snow, and the warmest and coldest days on record. Normals are the 1991–2020 averages at Allerton, 1 km from Allerton; records cover 1902–2026.
The year at a glance
- Precipitation a year
- 40.4 in1026 mm
- Snow a year
- Rare
- Last spring freeze
- Apr 19
- First fall freeze
- Oct 14
- Heating degree days
- 6,363
- Cooling degree days
- 873
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 95°35° (cooling, 1%).
Month by month
Allerton in January
Highs average 32°0° and lows 13°−11°, with 1.1 in27 mm of precipitation in a typical January.
- Record high
- 67°19° (2003)
- Record low
- −29°−34° (1912)
- Heating degree days
- 1328
- Cooling degree days
- 0
Allerton in February
Highs average 37°3° and lows 17°−9°, with 1.5 in39 mm of precipitation in a typical February.
- Record high
- 76°24° (2017)
- Record low
- −33°−36° (1905)
- Heating degree days
- 1075
- Cooling degree days
- 0
Allerton in March
Highs average 49°10° and lows 28°−2°, with 2.4 in60 mm of precipitation in a typical March.
- Record high
- 91°33° (2026)
- Record low
- −13°−25° (1913)
- Heating degree days
- 824
- Cooling degree days
- 1
Allerton in April
Highs average 62°16° and lows 38°3°, with 4 in102 mm of precipitation in a typical April.
- Record high
- 90°32° (1910)
- Record low
- 8°−13° (2006)
- Heating degree days
- 457
- Cooling degree days
- 4
Allerton in May
Highs average 71°22° and lows 50°10°, with 5.7 in144 mm of precipitation in a typical May.
- Record high
- 95°35° (2018)
- Record low
- 19°−7° (1907)
- Heating degree days
- 184
- Cooling degree days
- 47
Allerton in June
Highs average 80°27° and lows 60°16°, with 5.1 in131 mm of precipitation in a typical June.
- Record high
- 100°38° (1911)
- Record low
- 30°−1° (1903)
- Heating degree days
- 24
- Cooling degree days
- 175
Allerton in July
Highs average 85°29° and lows 64°18°, with 4.7 in120 mm of precipitation in a typical July.
- Record high
- 108°42° (1911)
- Record low
- 46°8° (1911)
- Heating degree days
- 4
- Cooling degree days
- 300
Allerton in August
Highs average 83°28° and lows 62°17°, with 4.9 in123 mm of precipitation in a typical August.
- Record high
- 108°42° (1918)
- Record low
- 39°4° (1915)
- Heating degree days
- 8
- Cooling degree days
- 239
Allerton in September
Highs average 76°24° and lows 54°12°, with 4.2 in107 mm of precipitation in a typical September.
- Record high
- 103°39° (1913)
- Record low
- 27°−3° (1908)
- Heating degree days
- 102
- Cooling degree days
- 93
Allerton in OctoberThis month
Highs average 64°18° and lows 41°5°, with 3.1 in78 mm of precipitation in a typical October.
- Record high
- 92°33° (2024)
- Record low
- 16°−9° (1910)
- Heating degree days
- 404
- Cooling degree days
- 14
Allerton in November
Highs average 49°9° and lows 28°−2°, with 2.2 in55 mm of precipitation in a typical November.
- Record high
- 80°27° (1909)
- Record low
- −4°−20° (1919)
- Heating degree days
- 792
- Cooling degree days
- 0
Allerton in December
Highs average 37°3° and lows 19°−7°, with 1.6 in41 mm of precipitation in a typical December.
- Record high
- 73°23° (2021)
- Record low
- −18°−28° (1917)
- Heating degree days
- 1161
- Cooling degree days
- 0