December weather forecastHartly, DE
December
Weather in December
December, the first month of the winter in Hartly, is still a chilly month, with an average temperature fluctuating between 34.7°F (1.5°C) and 45.9°F (7.7°C).Temperature
December sees a slight reduction in average high-temperature, with a shift from a cool 54°F (12.2°C) in November to a chilly 45.9°F (7.7°C). Throughout the month of December, Hartly sees a steady low-temperature average of 34.7°F (1.5°C).Humidity
In Hartly, the average relative humidity in December is 77%.Rainfall
In Hartly, during December, the rain falls for 11.5 days and regularly aggregates up to 3.43" (87mm) of precipitation. In Hartly, during the entire year, the rain falls for 169.2 days and collects up to 34.96" (888mm) of precipitation.Snowfall
Months with snowfall in Hartly are January through April, November and December. In December, it is snowing for 2.5 days. Throughout December, 0.91" (23mm) of snow is accumulated. In Hartly, during the entire year, snow falls for 14.4 days and aggregates up to 7.44" (189mm) of snow.Daylight
With an average of 9h and 30min of daylight, December has the shortest days of the year.On the first day of December, sunrise is at 7:03 am and sunset at 4:40 pm. On the last day of the month, sunrise is at 7:22 am and sunset at 4:50 pm EST.
Sunshine
The average sunshine in December is 5.2h.UV index
The months with the lowest UV index are January and December, with an average maximum UV index of 2. A UV Index estimate of 2, and below, represents a low threat to health from unprotected exposure to Sun's UV rays for the average person.Note: In December, a daily UV index of 2 turns into the following recommendations:
Extended sunlight exposure does not pose significant problems for most people, except for children, infants, and people with fair skin who always need shielding. Direct exposure to the Sun during its peak hours around mid-day should be minimized for safety. Loose clothes with a tight weave are optimal for safeguarding yourself against the Sun's rays. Be mindful! The reflection from snow can increase the Sun's UV radiation nearly twice.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in December
Hartly, DE
- Average high temperature in December: 45.9°F
The warmest month (with the highest average high temperature) is July (84.4°F).
The month with the lowest average high temperature is January (39.2°F).
- Average low temperature in December: 34.7°F
The month with the highest average low temperature is July (69.3°F).
The coldest month (with the lowest average low temperature) is January (27.9°F).
Average pressure in December
Hartly, DE
- Average pressure in December: 30.1"Hg
The month with the highest atmospheric pressure is November (30.12"Hg).
The month with the lowest atmospheric pressure is June (29.94"Hg).
Average wind speed in December
Hartly, DE
- Average wind speed in December: 8.7mph
The windiest months (with the highest average wind speed) are February and March (9.5mph).
The calmest month (with the lowest average wind speed) is August (6mph).
Average humidity in December
Hartly, DE
- Average humidity in December: 77%
The month with the highest relative humidity is May (79%).
The month with the lowest relative humidity is April (73%).
Average rainfall in December
Hartly, DE
- Average rainfall in December: 3.43"
The wettest month (with the highest rainfall) is August (3.86").
The driest month (with the least rainfall) is January (2.13").
Average rainfall days in December
Hartly, DE
- Average rainfall days in December: 11.5 days
The month with the highest number of rainy days is July (19 days).
The month with the least rainy days is November (9.3 days).
Average snowfall in December
Hartly, DE
- Average snowfall in December: 0.91"
The month with the highest snowfall is March (2.6").
The months with the least snowfall are May, June, July, August, September and October (0").
Average snowfall days in December
Hartly, DE
- Average snowfall days in December: 2.5 days
The month with the highest number of snowfall days is January (4.5 days).
The months with the least snowfall days are May, June, July, August, September and October (0 days).
Average daylight in December /
Average sunshine in December
Hartly, DE
- Average daylight in December: 9h and 30min
The month with the longest days is June (Average daylight: 14h and 54min).
The month with the shortest days is December (Average daylight: 9h and 30min).
- Average sunshine in December: 5h and 12min
The month with the most sunshine is July (Average sunshine: 10h and 42min).
The month with the least sunshine is February (Average sunshine: 5h and 6min).
Average sunshine days in December
Hartly, DE
- Average sunshine days in December: 16.8 days
The month with the most sunshine days is November (19.5 days).
The month with the least sunshine days is July (9.5 days).
Average UV index in December
Hartly, DE
- Average UV index in December: 2
The months with the highest UV index are May, June, July and August (UV index 6).
The months with the lowest UV index are January and December (UV index 2).
Average cloud cover in December
Hartly, DE
- Average cloud cover in December: 44
The months with the most cloud cover are February and March (Cloud cover 45).
The month with the least cloud cover is July (Cloud cover 29).
Average visibility in December
Hartly, DE
- 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).
