Contents
- Weather in December
- Frequently asked questions
- Average temperature in December
- Average pressure in December
- Average wind speed in December
- Average humidity in December
- Average rainfall in December
- Average rainfall days in December
- Average snowfall in December
- Average snowfall days in December
- Average daylight in December
- Average sunshine in December
- Average sunshine days in December
- Average UV index in December
- Average cloud cover in December
- Average visibility in December
Weather in December
Temperature
With December's onset, the weather shows a temperature decrease, transitioning from a frosty 43°F (6.1°C) in November to a freezing cold 29.8°F (-1.2°C). An average nighttime temperature of 19°F (-7.2°C) is witnessed in Harpers Ferry throughout December.Humidity
In December, the average relative humidity in Harpers Ferry, Iowa, is 84%.Rainfall
In Harpers Ferry, during December, the rain falls for 4.7 days and regularly aggregates up to 1.06" (27mm) of precipitation. Throughout the year, there are 124.7 rainfall days, and 22.56" (573mm) of precipitation is accumulated.Snowfall
January through May, October through December are months with snowfall. In Harpers Ferry, Iowa, during December, snow falls for 9.8 days and regularly aggregates up to 2.87" (73mm) of snow. Throughout the year, in Harpers Ferry, there are 44.5 snowfall days, and 15.47" (393mm) of snow is accumulated.Daylight
With an average of 9h and 0min of daylight, December has the shortest days of the year in Harpers Ferry, Iowa.On the first day of the month, sunrise is at 7:17 am and sunset at 4:30 pm. On the last day of December, sunrise is at 7:36 am and sunset at 4:39 pm CST.
Sunshine
The average sunshine in December is 3.9h.UV index
January, November and December, with an average maximum UV index of 1, are months with the lowest UV index. A UV Index of 2, and less, symbolizes a low health risk from exposure to the Sun's UV rays for the average person.Note: The daily high UV index of 1 in December translates into this advice:
While sun exposure does not greatly affect most, individuals with fair skin, babies, and children always need vigilant safeguarding. The mid-day Sun emits the most powerful UV radiation, so seek shade and minimize exposure. Always opt for UVA and UVB-resistant sunglasses on radiant days. Remember this! The UV radiation of the Sun can be nearly doubled by the reflective properties of snow.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
How cold is it in Harpers Ferry in December?
What is the average humidity in December in Harpers Ferry?
How much does it rain in Harpers Ferry in December?
How much does it snow in Harpers Ferry in December?
What is the month with the shortest days in Harpers Ferry?
What is the average length of the day in December in Harpers Ferry?
When is the sunrise / sunset in December in Harpers Ferry?
How many hours of sunshine does Harpers Ferry have in December?
What is the month with the lowest UV index in Harpers Ferry?
What is the UV index intensity in December in Harpers Ferry?
Average temperature in December
Harpers Ferry, IA
- Average high temperature in December: 29.8°F
The warmest month (with the highest average high temperature) is July (79.9°F).
The month with the lowest average high temperature is January (23.2°F).
- Average low temperature in December: 19°F
The month with the highest average low temperature is July (61.9°F).
The coldest month (with the lowest average low temperature) is January (10.6°F).
Average pressure in December
Harpers Ferry, IA
- Average pressure in December: 30.1"Hg
The month with the highest atmospheric pressure is January (30.13"Hg).
The month with the lowest atmospheric pressure is June (29.9"Hg).
Average wind speed in December
Harpers Ferry, IA
- Average wind speed in December: 9.1mph
The windiest month (with the highest average wind speed) is April (9.9mph).
The calmest months (with the lowest average wind speed) are July and August (6.6mph).
Average humidity in December
Harpers Ferry, IA
- Average humidity in December: 84%
The months with the highest relative humidity are January and February (88%).
The month with the lowest relative humidity is October (76%).
Average rainfall in December
Harpers Ferry, IA
- Average rainfall in December: 1.06"
The wettest month (with the highest rainfall) is June (3.9").
The driest month (with the least rainfall) is January (0.75").
Average rainfall days in December
Harpers Ferry, IA
- Average rainfall days in December: 4.7 days
The month with the highest number of rainy days is June (18.6 days).
The month with the least rainy days is February (3.6 days).
Average snowfall in December
Harpers Ferry, IA
- Average snowfall in December: 2.87"
The month with the highest snowfall is February (3.94").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days in December
Harpers Ferry, IA
- Average snowfall days in December: 9.8 days
The month with the highest number of snowfall days is January (11.7 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in December /
Average sunshine in December
Harpers Ferry, IA
- Average daylight in December: 9h and 0min
The month with the longest days is June (Average daylight: 15h and 18min).
The month with the shortest days is December (Average daylight: 9h and 0min).
- Average sunshine in December: 3h and 5min
The month with the most sunshine is August (Average sunshine: 9h and 48min).
The month with the least sunshine is January (Average sunshine: 3h and 24min).
Average sunshine days in December
Harpers Ferry, IA
- Average sunshine days in December: 17.6 days
The month with the most sunshine days is November (19.4 days).
The month with the least sunshine days is June (9.6 days).
Average UV index in December
Harpers Ferry, IA
- Average UV index in December: 1
The months with the highest UV index are June and July (UV index 6).
The months with the lowest UV index are January, November and December (UV index 1).
Average cloud cover in December
Harpers Ferry, IA
- Average cloud cover in December: 60
The month with the most cloud cover is January (Cloud cover 64).
The month with the least cloud cover is August (Cloud cover 32).
Average visibility in December
Harpers Ferry, IA
- Average visibility in December: 6mi
The months with the highest visibility are March, April, May, June, October, November and December (6mi).
The months with the lowest visibility are January, February, July, August and September (5mi).
Harpers Ferry, Iowa, USA
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