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
Rosslyn Farms's transition into December involves a shift in temperature, receding from a chilly 49.3°F (9.6°C) in November to a wintry 39.7°F (4.3°C). Rosslyn Farms temperatures generally rest at a low of 28.4°F (-2°C) during the December nights.Humidity
In December, the average relative humidity is 83%.Rainfall
In December, the rain falls for 8.2 days. Throughout December, 0.87" (22mm) of precipitation is accumulated. Throughout the year, there are 132.6 rainfall days, and 11.5" (292mm) of precipitation is accumulated.Snowfall
Months with snowfall are January through April, November and December. In Rosslyn Farms, during December, snow falls for 6.4 days and regularly aggregates up to 0.59" (15mm) of snow. In Rosslyn Farms, during the entire year, snow falls for 32.5 days and aggregates up to 3.66" (93mm) of snow.Daylight
December has the shortest days of the year, with an average of 9h and 18min of daylight.On the first day of the month, sunrise is at 7:24 am and sunset at 4:54 pm. On the last day of December, in Rosslyn Farms, sunrise is at 7:43 am and sunset at 5:04 pm EST.
Sunshine
In December, the average sunshine is 3.4h.UV index
With an average maximum UV index of 1, December is the month with the lowest UV index. A UV Index value of 2, and less, symbolizes a low health risk from unprotected exposure to Sun's UV rays for average individuals.Note: The maximum UV index of 1 during December translates into these guidelines:
Despite most people tolerating extended sun exposure, it is critical to always protect those with sensitive skin, infants, and children. Sun's radiation is most powerful around mid-day, so it's best to limit outdoor activities during this time. Arm yourself against UV rays' harm with protective apparel and UV-filtering shades. Caution! The reflection of snow can nearly double the intensity of the Sun's UV radiation.
Frequently asked questions
How cold does it get in Rosslyn Farms in December?
What is the average humidity in December in Rosslyn Farms?
How much does it rain in Rosslyn Farms in December?
How many days does it snow in December in Rosslyn Farms?
What is the month with the shortest days in Rosslyn Farms?
What is the average length of the day in December in Rosslyn Farms?
When is the sunrise / sunset in December in Rosslyn Farms?
How long on average sun shines in December in Rosslyn Farms?
When is the lowest UV index in Rosslyn Farms?
How high is the UV index in December in Rosslyn Farms?
Average temperature in December
Rosslyn Farms, PA
- Average high temperature in December: 39.7°F
The warmest month (with the highest average high temperature) is July (83.7°F).
The month with the lowest average high temperature is January (33.4°F).
- Average low temperature in December: 28.4°F
The month with the highest average low temperature is July (62.2°F).
The coldest month (with the lowest average low temperature) is January (21°F).
Average pressure in December
Rosslyn Farms, PA
- Average pressure in December: 30.11"Hg
The month with the highest atmospheric pressure is November (30.13"Hg).
The month with the lowest atmospheric pressure is June (29.95"Hg).
Average wind speed in December
Rosslyn Farms, PA
- Average wind speed in December: 7.3mph
The windiest month (with the highest average wind speed) is January (7.9mph).
The calmest months (with the lowest average wind speed) are July and August (4.7mph).
Average humidity in December
Rosslyn Farms, PA
- Average humidity in December: 83%
The month with the highest relative humidity is February (85%).
The months with the lowest relative humidity are July and August (75%).
Average rainfall in December
Rosslyn Farms, PA
- Average rainfall in December: 0.87"
The wettest month (with the highest rainfall) is July (1.34").
The driest month (with the least rainfall) is November (0.67").
Average rainfall days in December
Rosslyn Farms, PA
- Average rainfall days in December: 8.2 days
The month with the highest number of rainy days is July (15.6 days).
The month with the least rainy days is February (6.4 days).
Average snowfall in December
Rosslyn Farms, PA
- Average snowfall in December: 0.59"
The month with the highest snowfall is February (0.98").
The months with the least snowfall are May, June, July, August, September and October (0").
Average snowfall days in December
Rosslyn Farms, PA
- Average snowfall days in December: 6.4 days
The month with the highest number of snowfall days is January (9.3 days).
The months with the least snowfall days are May, June, July, August and September (0 days).
Average daylight in December /
Average sunshine in December
Rosslyn Farms, PA
- Average daylight in December: 9h and 2min
The month with the longest days is June (Average daylight: 15h and 0min).
The month with the shortest days is December (Average daylight: 9h and 18min).
- Average sunshine in December: 3h and 2min
The month with the most sunshine is August (Average sunshine: 10h and 12min).
The month with the least sunshine is January (Average sunshine: 3h and 0min).
Average sunshine days in December
Rosslyn Farms, PA
- Average sunshine days in December: 18.5 days
The month with the most sunshine days is November (19.6 days).
The month with the least sunshine days is May (12.2 days).
Average UV index in December
Rosslyn Farms, PA
- Average UV index in December: 1
The months with the highest UV index are June, July and August (UV index 6).
The month with the lowest UV index is December (UV index 1).
Average cloud cover in December
Rosslyn Farms, PA
- Average cloud cover in December: 64
The month with the most cloud cover is January (Cloud cover 68).
The month with the least cloud cover is August (Cloud cover 33).
Average visibility in December
Rosslyn Farms, PA
- Average visibility in December: 5mi
The months with the highest visibility are April, June, July, August and November (6mi).
The months with the lowest visibility are January, February, March, May, September, October and December (5mi).
Rosslyn Farms, Pennsylvania, USA
Weather forecast for your location
2. Allow the app to use your location
