Harpers Ferry weather by month
What a typical year looks like in Harpers Ferry, Iowa: average highs and lows, rain and snow, and the warmest and coldest days on record. Normals are the 1991–2020 averages at Prairie Du Chien, 17 km from Harpers Ferry; records cover 1893–2026.
The year at a glance
- Precipitation a year
- 37.7 in959 mm
- Snow a year
- 34 in86 cm
- Last spring freeze
- Apr 26
- First fall freeze
- Oct 10
- Heating degree days
- 7,015
- Cooling degree days
- 748
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
Harpers Ferry in January
Highs average 27°−3° and lows 10°−12°, with 1.2 in31 mm of precipitation and 9 in23 cm of snow in a typical January.
- Record high
- 66°19° (1897)
- Record low
- −37°−38° (1951)
- Heating degree days
- 1444
- Cooling degree days
- 0
Harpers Ferry in February
Highs average 32°0° and lows 13°−10°, with 1.3 in32 mm of precipitation and 9 in22 cm of snow in a typical February.
- Record high
- 73°23° (2024)
- Record low
- −36°−38° (1996)
- Heating degree days
- 1184
- Cooling degree days
- 0
Harpers Ferry in March
Highs average 45°7° and lows 25°−4°, with 2.1 in52 mm of precipitation and 4 in11 cm of snow in a typical March.
- Record high
- 89°32° (1895)
- Record low
- −33°−36° (1962)
- Heating degree days
- 934
- Cooling degree days
- 1
Harpers Ferry in April
Highs average 59°15° and lows 37°3°, with 4 in103 mm of precipitation and 1.4 in3.6 cm of snow in a typical April.
- Record high
- 96°36° (1980)
- Record low
- 0°−18° (1972)
- Heating degree days
- 525
- Cooling degree days
- 3
Harpers Ferry in May
Highs average 70°21° and lows 48°9°, with 4.7 in119 mm of precipitation in a typical May.
- Record high
- 109°43° (1934)
- Record low
- 21°−6° (1944)
- Heating degree days
- 222
- Cooling degree days
- 42
Harpers Ferry in June
Highs average 80°26° and lows 59°15°, with 5.8 in148 mm of precipitation in a typical June.
- Record high
- 105°41° (1931)
- Record low
- 34°1° (1894)
- Heating degree days
- 33
- Cooling degree days
- 160
Harpers Ferry in July
Highs average 83°28° and lows 63°17°, with 4.1 in105 mm of precipitation in a typical July.
- Record high
- 110°43° (1901)
- Record low
- 38°3° (1895)
- Heating degree days
- 5
- Cooling degree days
- 256
Harpers Ferry in August
Highs average 81°27° and lows 61°16°, with 4.2 in105 mm of precipitation in a typical August.
- Record high
- 106°41° (1894)
- Record low
- 35°2° (1896)
- Heating degree days
- 12
- Cooling degree days
- 203
Harpers Ferry in September
Highs average 74°23° and lows 52°11°, with 4 in101 mm of precipitation in a typical September.
- Record high
- 104°40° (1939)
- Record low
- 20°−7° (1893)
- Heating degree days
- 130
- Cooling degree days
- 73
Harpers Ferry in OctoberThis month
Highs average 62°17° and lows 40°5°, with 2.7 in69 mm of precipitation and 0.2 in0.5 cm of snow in a typical October.
- Record high
- 93°34° (1963)
- Record low
- 4°−16° (1925)
- Heating degree days
- 447
- Cooling degree days
- 10
Harpers Ferry in November
Highs average 46°8° and lows 28°−2°, with 2.1 in54 mm of precipitation and 1.5 in3.8 cm of snow in a typical November.
- Record high
- 85°29° (1999)
- Record low
- −17°−27° (1977)
- Heating degree days
- 839
- Cooling degree days
- 0
Harpers Ferry in December
Highs average 33°0° and lows 17°−8°, with 1.6 in40 mm of precipitation and 9 in22 cm of snow in a typical December.
- Record high
- 70°21° (2021)
- Record low
- −26°−32° (1950)
- Heating degree days
- 1240
- Cooling degree days
- 0