Postville weather by month
What a typical year looks like in Postville, Iowa: average highs and lows, rain and snow, and the warmest and coldest days on record. Normals are the 1991–2020 averages at Postville, 1 km from Postville; records cover 1901–2026.
The year at a glance
- Precipitation a year
- 38.9 in989 mm
- Snow a year
- 40 in101 cm
- Last spring freeze
- Apr 29
- First fall freeze
- Oct 4
- Heating degree days
- 7,520
- Cooling degree days
- 614
Freeze dates are medians (half of years earlier, half later). Degree days use a 65°F base; HVAC design temperatures here are −14°−26° (heating, 99%) and 92°33° (cooling, 1%).
Month by month
Postville in January
Highs average 26°−4° and lows 7°−14°, with 1.1 in28 mm of precipitation and 12 in30 cm of snow in a typical January.
- Record high
- 60°16° (2025)
- Record low
- −35°−37° (1912)
- Heating degree days
- 1502
- Cooling degree days
- 0
Postville in February
Highs average 30°−1° and lows 11°−12°, with 1.2 in31 mm of precipitation and 10 in26 cm of snow in a typical February.
- Record high
- 72°22° (2024)
- Record low
- −29°−34° (1905)
- Heating degree days
- 1254
- Cooling degree days
- 0
Postville in March
Highs average 43°6° and lows 22°−5°, with 2.1 in53 mm of precipitation and 5 in13 cm of snow in a typical March.
- Record high
- 83°28° (1910)
- Record low
- −18°−28° (1913)
- Heating degree days
- 1002
- Cooling degree days
- 0
Postville in April
Highs average 58°14° and lows 34°1°, with 4.1 in105 mm of precipitation and 1.6 in4.1 cm of snow in a typical April.
- Record high
- 88°31° (1902)
- Record low
- 6°−14° (1936)
- Heating degree days
- 578
- Cooling degree days
- 1
Postville in May
Highs average 69°21° and lows 47°8°, with 5 in127 mm of precipitation in a typical May.
- Record high
- 105°41° (1934)
- Record low
- 20°−7° (1929)
- Heating degree days
- 246
- Cooling degree days
- 34
Postville in June
Highs average 79°26° and lows 58°14°, with 5.9 in149 mm of precipitation in a typical June.
- Record high
- 104°40° (1934)
- Record low
- 34°1° (1945)
- Heating degree days
- 37
- Cooling degree days
- 138
Postville in July
Highs average 83°28° and lows 61°16°, with 4.5 in115 mm of precipitation in a typical July.
- Record high
- 108°42° (1901)
- Record low
- 39°4° (1907)
- Heating degree days
- 8
- Cooling degree days
- 221
Postville in August
Highs average 81°27° and lows 58°15°, with 4.4 in111 mm of precipitation in a typical August.
- Record high
- 102°39° (1988)
- Record low
- 35°2° (1934)
- Heating degree days
- 22
- Cooling degree days
- 161
Postville in September
Highs average 74°23° and lows 49°10°, with 4 in101 mm of precipitation in a typical September.
- Record high
- 99°37° (1939)
- Record low
- 20°−7° (1918)
- Heating degree days
- 155
- Cooling degree days
- 53
Postville in OctoberThis month
Highs average 61°16° and lows 37°3°, with 3 in76 mm of precipitation and 0.1 in0.3 cm of snow in a typical October.
- Record high
- 90°32° (2023)
- Record low
- −7°−22° (1925)
- Heating degree days
- 508
- Cooling degree days
- 6
Postville in November
Highs average 45°7° and lows 26°−4°, with 2.1 in53 mm of precipitation and 2.7 in6.9 cm of snow in a typical November.
- Record high
- 76°24° (1933)
- Record low
- −12°−24° (1989)
- Heating degree days
- 897
- Cooling degree days
- 0
Postville in December
Highs average 31°0° and lows 14°−10°, with 1.6 in40 mm of precipitation and 8 in20 cm of snow in a typical December.
- Record high
- 68°20° (2021)
- Record low
- −27°−33° (1989)
- Heating degree days
- 1311
- Cooling degree days
- 0