Marengo weather by month
What a typical year looks like in Marengo, Iowa: average highs and lows, rain and snow, and the warmest and coldest days on record. Normals are the 1991–2020 averages at Belle Plaine, 20 km from Marengo; records cover 1893–2026.
The year at a glance
- Precipitation a year
- 36 in914 mm
- Snow a year
- 28 in71 cm
- Last spring freeze
- Apr 27
- First fall freeze
- Oct 6
- Heating degree days
- 6,869
- Cooling degree days
- 784
Freeze dates are medians (half of years earlier, half later). Degree days use a 65°F base; HVAC design temperatures here are −12°−24° (heating, 99%) and 93°34° (cooling, 1%).
Month by month
Marengo in January
Highs average 28°−2° and lows 10°−12°, with 1.1 in28 mm of precipitation and 8 in20 cm of snow in a typical January.
- Record high
- 65°18° (1989)
- Record low
- −38°−39° (2009)
- Heating degree days
- 1418
- Cooling degree days
- 0
Marengo in February
Highs average 33°0° and lows 14°−10°, with 1.3 in33 mm of precipitation and 7 in19 cm of snow in a typical February.
- Record high
- 76°24° (2024)
- Record low
- −35°−37° (1996)
- Heating degree days
- 1161
- Cooling degree days
- 0
Marengo in March
Highs average 46°8° and lows 26°−3°, with 2 in52 mm of precipitation and 3 in9 cm of snow in a typical March.
- Record high
- 89°32° (2026)
- Record low
- −23°−31° (1962)
- Heating degree days
- 903
- Cooling degree days
- 1
Marengo in April
Highs average 60°16° and lows 37°3°, with 3.7 in93 mm of precipitation and 0.8 in2 cm of snow in a typical April.
- Record high
- 95°35° (1986)
- Record low
- 7°−14° (1904)
- Heating degree days
- 498
- Cooling degree days
- 4
Marengo in May
Highs average 71°22° and lows 49°10°, with 4.4 in113 mm of precipitation in a typical May.
- Record high
- 108°42° (1934)
- Record low
- 22°−6° (1907)
- Heating degree days
- 202
- Cooling degree days
- 49
Marengo in June
Highs average 80°27° and lows 60°15°, with 5.2 in133 mm of precipitation in a typical June.
- Record high
- 106°41° (1934)
- Record low
- 35°2° (1897)
- Heating degree days
- 27
- Cooling degree days
- 177
Marengo in July
Highs average 84°29° and lows 63°17°, with 4.1 in103 mm of precipitation in a typical July.
- Record high
- 109°43° (1936)
- Record low
- 42°6° (1908)
- Heating degree days
- 5
- Cooling degree days
- 261
Marengo in August
Highs average 82°28° and lows 60°16°, with 4.1 in104 mm of precipitation in a typical August.
- Record high
- 111°44° (1936)
- Record low
- 36°2° (1915)
- Heating degree days
- 13
- Cooling degree days
- 203
Marengo in September
Highs average 76°24° and lows 51°11°, with 3.6 in90 mm of precipitation in a typical September.
- Record high
- 104°40° (1925)
- Record low
- 23°−5° (1899)
- Heating degree days
- 126
- Cooling degree days
- 79
Marengo in OctoberThis month
Highs average 63°17° and lows 39°4°, with 2.9 in73 mm of precipitation and 0.4 in1 cm of snow in a typical October.
- Record high
- 93°34° (1953)
- Record low
- −2°−19° (1925)
- Heating degree days
- 446
- Cooling degree days
- 10
Marengo in November
Highs average 47°8° and lows 27°−3°, with 2.1 in54 mm of precipitation and 1.8 in4.6 cm of snow in a typical November.
- Record high
- 82°28° (1924)
- Record low
- −10°−23° (1897)
- Heating degree days
- 836
- Cooling degree days
- 0
Marengo in December
Highs average 34°1° and lows 17°−8°, with 1.6 in40 mm of precipitation and 6 in16 cm of snow in a typical December.
- Record high
- 70°21° (2012)
- Record low
- −30°−34° (1985)
- Heating degree days
- 1234
- Cooling degree days
- 0