Griswold weather by month
What a typical year looks like in Griswold, Iowa: average highs and lows, rain and snow, and the warmest and coldest days on record. Normals are the 1991–2020 averages at Atlantic 1 NE, 23 km from Griswold; records cover 1893–2026.
The year at a glance
- Precipitation a year
- 37.1 in943 mm
- Snow a year
- 27 in69 cm
- Last spring freeze
- Apr 27
- First fall freeze
- Sep 29
- Heating degree days
- 6,639
- Cooling degree days
- 940
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 95°35° (cooling, 1%).
Month by month
Griswold in January
Highs average 31°0° and lows 10°−12°, with 0.86 in22 mm of precipitation and 5 in13 cm of snow in a typical January.
- Record high
- 67°19° (2002)
- Record low
- −37°−38° (1974)
- Heating degree days
- 1378
- Cooling degree days
- 0
Griswold in February
Highs average 36°2° and lows 14°−10°, with 1.1 in29 mm of precipitation and 8 in20 cm of snow in a typical February.
- Record high
- 78°26° (2024)
- Record low
- −36°−38° (1905)
- Heating degree days
- 1123
- Cooling degree days
- 0
Griswold in March
Highs average 50°10° and lows 25°−4°, with 1.9 in48 mm of precipitation and 3 in9 cm of snow in a typical March.
- Record high
- 94°34° (2026)
- Record low
- −32°−36° (1962)
- Heating degree days
- 857
- Cooling degree days
- 1
Griswold in April
Highs average 63°17° and lows 36°2°, with 3.8 in97 mm of precipitation and 0.5 in1.3 cm of snow in a typical April.
- Record high
- 94°34° (1910)
- Record low
- 4°−16° (1899)
- Heating degree days
- 478
- Cooling degree days
- 7
Griswold in May
Highs average 73°23° and lows 49°10°, with 5.4 in138 mm of precipitation in a typical May.
- Record high
- 105°41° (1934)
- Record low
- 17°−8° (1908)
- Heating degree days
- 180
- Cooling degree days
- 62
Griswold in June
Highs average 83°28° and lows 60°15°, with 5.7 in146 mm of precipitation in a typical June.
- Record high
- 106°41° (1937)
- Record low
- 32°0° (1894)
- Heating degree days
- 19
- Cooling degree days
- 208
Griswold in July
Highs average 86°30° and lows 64°18°, with 4.4 in112 mm of precipitation in a typical July.
- Record high
- 117°47° (1936)
- Record low
- 37°3° (1895)
- Heating degree days
- 3
- Cooling degree days
- 307
Griswold in August
Highs average 84°29° and lows 61°16°, with 4.4 in113 mm of precipitation in a typical August.
- Record high
- 111°44° (1918)
- Record low
- 33°1° (1893)
- Heating degree days
- 11
- Cooling degree days
- 243
Griswold in September
Highs average 78°26° and lows 51°10°, with 3.4 in85 mm of precipitation in a typical September.
- Record high
- 104°40° (1913)
- Record low
- 17°−8° (1899)
- Heating degree days
- 114
- Cooling degree days
- 99
Griswold in OctoberThis month
Highs average 65°18° and lows 38°3°, with 2.9 in74 mm of precipitation and 0.7 in1.8 cm of snow in a typical October.
- Record high
- 96°36° (1893)
- Record low
- 1°−17° (1925)
- Heating degree days
- 430
- Cooling degree days
- 13
Griswold in November
Highs average 49°10° and lows 25°−4°, with 1.7 in42 mm of precipitation and 2 in5.1 cm of snow in a typical November.
- Record high
- 83°28° (1999)
- Record low
- −16°−27° (1952)
- Heating degree days
- 831
- Cooling degree days
- 0
Griswold in December
Highs average 36°2° and lows 15°−9°, with 1.5 in38 mm of precipitation and 8 in20 cm of snow in a typical December.
- Record high
- 72°22° (2021)
- Record low
- −33°−36° (1983)
- Heating degree days
- 1215
- Cooling degree days
- 0