Newton weather by month
What a typical year looks like in Newton, Iowa: average highs and lows, rain and snow, and the warmest and coldest days on record. Normals are the 1991–2020 averages at Grinnell 3 SW, 24 km from Newton; records cover 1893–2026.
The year at a glance
- Precipitation a year
- 38.2 in970 mm
- Snow a year
- 31 in79 cm
- Last spring freeze
- May 6
- First fall freeze
- Oct 3
- Heating degree days
- 7,038
- Cooling degree days
- 693
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 92°33° (cooling, 1%).
Month by month
Newton in January
Highs average 28°−2° and lows 10°−12°, with 1.1 in28 mm of precipitation and 9 in23 cm of snow in a typical January.
- Record high
- 64°18° (2003)
- Record low
- −34°−37° (1974)
- Heating degree days
- 1418
- Cooling degree days
- 0
Newton in February
Highs average 33°1° and lows 14°−10°, with 1.6 in39 mm of precipitation and 9 in23 cm of snow in a typical February.
- Record high
- 77°25° (2024)
- Record low
- −35°−37° (1996)
- Heating degree days
- 1168
- Cooling degree days
- 0
Newton in March
Highs average 46°8° and lows 25°−4°, with 2.2 in56 mm of precipitation and 3 in9 cm of snow in a typical March.
- Record high
- 90°32° (1910)
- Record low
- −17°−27° (1962)
- Heating degree days
- 918
- Cooling degree days
- 1
Newton in April
Highs average 59°15° and lows 35°2°, with 3.9 in99 mm of precipitation and 0.6 in1.5 cm of snow in a typical April.
- Record high
- 92°33° (1910)
- Record low
- 1°−17° (1982)
- Heating degree days
- 536
- Cooling degree days
- 3
Newton in May
Highs average 70°21° and lows 47°8°, with 5.1 in129 mm of precipitation in a typical May.
- Record high
- 107°42° (1934)
- Record low
- 19°−7° (2005)
- Heating degree days
- 238
- Cooling degree days
- 37
Newton in June
Highs average 80°26° and lows 58°14°, with 5.5 in140 mm of precipitation in a typical June.
- Record high
- 105°41° (1934)
- Record low
- 35°2° (1983)
- Heating degree days
- 40
- Cooling degree days
- 149
Newton in July
Highs average 83°29° and lows 62°17°, with 4 in101 mm of precipitation in a typical July.
- Record high
- 108°42° (1934)
- Record low
- 40°4° (1971)
- Heating degree days
- 7
- Cooling degree days
- 242
Newton in August
Highs average 81°27° and lows 59°15°, with 4.4 in111 mm of precipitation in a typical August.
- Record high
- 110°43° (1934)
- Record low
- 36°2° (1950)
- Heating degree days
- 20
- Cooling degree days
- 181
Newton in September
Highs average 75°24° and lows 50°10°, with 3.7 in94 mm of precipitation in a typical September.
- Record high
- 101°38° (1925)
- Record low
- 21°−6° (1984)
- Heating degree days
- 140
- Cooling degree days
- 71
Newton in OctoberThis month
Highs average 62°17° and lows 38°3°, with 3.2 in82 mm of precipitation and 0.5 in1.3 cm of snow in a typical October.
- Record high
- 95°35° (1963)
- Record low
- 2°−17° (1925)
- Heating degree days
- 466
- Cooling degree days
- 9
Newton in November
Highs average 47°8° and lows 26°−3°, with 2 in50 mm of precipitation and 1.5 in3.8 cm of snow in a typical November.
- Record high
- 82°28° (1968)
- Record low
- −15°−26° (1976)
- Heating degree days
- 852
- Cooling degree days
- 0
Newton in December
Highs average 34°1° and lows 16°−9°, with 1.6 in41 mm of precipitation and 7 in18 cm of snow in a typical December.
- Record high
- 69°21° (1998)
- Record low
- −32°−36° (1985)
- Heating degree days
- 1235
- Cooling degree days
- 0