December weather forecastHarlan, IA
December
Weather in December
December, the first month of the winter in Harlan, is also an icy month, with an average temperature fluctuating between 20.8°F (-6.2°C) and 32.2°F (0.1°C).Temperature
Harlan, Iowa, experiences a temperature shift at the start of December, with average high-temperatures adjusting from a frosty 46.2°F (7.9°C) in November to an icy 32.2°F (0.1°C). Harlan encounters a steady low-temperature average of 20.8°F (-6.2°C) throughout the month of December.Humidity
The average relative humidity in December in Harlan is 79%.Rainfall
In December, in Harlan, the rain falls for 4.2 days. Throughout December, 0.71" (18mm) of precipitation is accumulated. In Harlan, during the entire year, the rain falls for 113.5 days and collects up to 15.71" (399mm) of precipitation.Snowfall
January through May, October through December are months with snowfall. In Harlan, Iowa, in December, during 6.1 snowfall days, 1.06" (27mm) of snow is typically accumulated. In Harlan, during the entire year, snow falls for 31.5 days and aggregates up to 7.13" (181mm) of snow.Daylight
The month with the shortest days in Harlan is December, with an average of 9h and 12min of daylight.On the first day of the month, sunrise is at 7:29 am and sunset at 4:51 pm. On the last day of December, in Harlan, sunrise is at 7:48 am and sunset at 5:01 pm CST.
Sunshine
In December, the average sunshine is 4.8h.UV index
January, February, October through December, with an average maximum UV index of 2, are months with the lowest UV index in Harlan. A UV Index estimate of 2, and below, represents a low threat to health from unprotected exposure to Sun's UV rays for the ordinary person.Note: The average daily UV index of 2 in December transforms into the following instructions:
Protection from prolonged sun exposure is necessary for babies, children, and individuals with sensitive skin. The midday Sun can be harmful due to its potent UV radiation; seek shade and reduce exposure. Select sunglasses that boast both UVA and UVB protection to limit the adverse effects of the sun on the eyes. Pay attention! The reflection of snow can enhance the Sun's UV radiation almost double.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in December
Harlan, IA
- Average high temperature in December: 32.2°F
The warmest month (with the highest average high temperature) is July (82.6°F).
The month with the lowest average high temperature is January (27.3°F).
- Average low temperature in December: 20.8°F
The month with the highest average low temperature is July (64.9°F).
The coldest month (with the lowest average low temperature) is January (14.5°F).
Average pressure in December
Harlan, IA
- Average pressure in December: 30.13"Hg
The month with the highest atmospheric pressure is January (30.16"Hg).
The month with the lowest atmospheric pressure is June (29.87"Hg).
Average wind speed in December
Harlan, IA
- Average wind speed in December: 10.1mph
The windiest month (with the highest average wind speed) is April (10.9mph).
The calmest month (with the lowest average wind speed) is July (7.2mph).
Average humidity in December
Harlan, IA
- Average humidity in December: 79%
The month with the highest relative humidity is January (83%).
The month with the lowest relative humidity is October (68%).
Average rainfall in December
Harlan, IA
- Average rainfall in December: 0.71"
The wettest month (with the highest rainfall) is June (2.64").
The driest month (with the least rainfall) is January (0.43").
Average rainfall days in December
Harlan, IA
- Average rainfall days in December: 4.2 days
The month with the highest number of rainy days is June (16.1 days).
The month with the least rainy days is February (2.8 days).
Average snowfall in December
Harlan, IA
- Average snowfall in December: 1.06"
The month with the highest snowfall is February (2.09").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days in December
Harlan, IA
- Average snowfall days in December: 6.1 days
The month with the highest number of snowfall days is January (8.3 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in December /
Average sunshine in December
Harlan, IA
- Average daylight in December: 9h and 12min
The month with the longest days is June (Average daylight: 15h and 12min).
The month with the shortest days is December (Average daylight: 9h and 12min).
- Average sunshine in December: 4h and 48min
The month with the most sunshine is July (Average sunshine: 10h and 24min).
The month with the least sunshine is January (Average sunshine: 4h and 30min).
Average sunshine days in December
Harlan, IA
- Average sunshine days in December: 21.6 days
The month with the most sunshine days is December (21.6 days).
The month with the least sunshine days is June (11.4 days).
Average UV index in December
Harlan, IA
- Average UV index in December: 2
The months with the highest UV index are June, July and August (UV index 6).
The months with the lowest UV index are January, February, October, November and December (UV index 2).
Average cloud cover in December
Harlan, IA
- Average cloud cover in December: 48
The month with the most cloud cover is January (Cloud cover 52).
The month with the least cloud cover is July (Cloud cover 27).
Average visibility in December
Harlan, IA
- Average visibility in December: 6mi
The months with the highest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).
The months with the lowest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).
