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
A moderate decline in the average high-temperature is seen during December, decreasing from a frosty 46.8°F (8.2°C) in November to a wintry 37°F (2.8°C). Throughout December nights, Jamestown experiences a consistent temperature average of 26.4°F (-3.1°C).Humidity
The average relative humidity in December is 87%.Rainfall
In December, the rain falls for 11.9 days. Throughout December, 1.85" (47mm) of precipitation is accumulated. In Jamestown, during the entire year, the rain falls for 167.1 days and collects up to 24.25" (616mm) of precipitation.Snowfall
Months with snowfall are January through May, October through December. In Jamestown, in December, during 16.5 snowfall days, 4.88" (124mm) of snow is typically accumulated. In Jamestown, during the entire year, snow falls for 79.6 days and aggregates up to 25" (635mm) of snow.Daylight
December has the shortest days of the year, 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 4:52 pm. On the last day of December, sunrise is at 7:48 am and sunset at 5:02 pm EST.
Sunshine
The average sunshine in December in Jamestown is 2.8h.UV index
With an average maximum UV index of 1, December is the month with the lowest UV index in Jamestown. A UV Index of 2, and less, symbolizes a low health risk from unsafe exposure to UV radiation for the ordinary person.Note: The UV index of 1 in December translates into these instructions:
Children necessitate constant protection from sunlight, unlike the majority, who can remain under the sun for about an hour without burning. The midday Sun can be dangerous due to its intense radiation; always find shade and reduce exposure. For minimizing sun-related eye damage, always choose sunglasses with UVA and UVB coverage. Be aware! The reflective nature of snow can magnify the Sun's UV radiation almost twofold.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
How cold is December?
What is the average humidity in December?
How much does it rain in December?
How much does it snow in December?
What is the month with the shortest days?
How many hours of daylight does Jamestown have in December?
What time are sunrise and sunset in December?
How long on average sun shines in December?
When is the lowest UV index?
What is the UV index reading in December in Jamestown?
Average temperature in December
Jamestown, PA
- Average high temperature in December: 37°F
The warmest month (with the highest average high temperature) is July (80.8°F).
The month with the lowest average high temperature is January (30.6°F).
- Average low temperature in December: 26.4°F
The month with the highest average low temperature is July (59.5°F).
The coldest month (with the lowest average low temperature) is January (18.1°F).
Average pressure in December
Jamestown, PA
- Average pressure in December: 30.09"Hg
The month with the highest atmospheric pressure is November (30.11"Hg).
The month with the lowest atmospheric pressure is June (29.94"Hg).
Average wind speed in December
Jamestown, PA
- Average wind speed in December: 7.6mph
The windiest month (with the highest average wind speed) is January (8.1mph).
The calmest month (with the lowest average wind speed) is July (5.1mph).
Average humidity in December
Jamestown, PA
- Average humidity in December: 87%
The month with the highest relative humidity is February (89%).
The months with the lowest relative humidity are May, June and July (79%).
Average rainfall in December
Jamestown, PA
- Average rainfall in December: 1.85"
The wettest month (with the highest rainfall) is October (2.52").
The driest month (with the least rainfall) is September (1.57").
Average rainfall days in December
Jamestown, PA
- Average rainfall days in December: 11.9 days
The month with the highest number of rainy days is May (17.6 days).
The month with the least rainy days is January (8 days).
Average snowfall in December
Jamestown, PA
- Average snowfall in December: 4.88"
The month with the highest snowfall is January (6.38").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days in December
Jamestown, PA
- Average snowfall days in December: 16.5 days
The month with the highest number of snowfall days is January (19.9 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in December /
Average sunshine in December
Jamestown, PA
- Average daylight in December: 9h and 1min
The month with the longest days is June (Average daylight: 15h and 6min).
The month with the shortest days is December (Average daylight: 9h and 12min).
- Average sunshine in December: 2h and 5min
The months with the most sunshine are July and August (Average sunshine: 9h and 54min).
The month with the least sunshine is January (Average sunshine: 2h and 24min).
Average sunshine days in December
Jamestown, PA
- Average sunshine days in December: 7.5 days
The month with the most sunshine days is August (12.6 days).
The month with the least sunshine days is February (6.3 days).
Average UV index in December
Jamestown, PA
- Average UV index in December: 1
The month with the highest UV index is July (UV index 6).
The month with the lowest UV index is December (UV index 1).
Average cloud cover in December
Jamestown, PA
- Average cloud cover in December: 71
The month with the most cloud cover is January (Cloud cover 76).
The month with the least cloud cover is August (Cloud cover 36).
Average visibility in December
Jamestown, PA
- Average visibility in December: 4mi
The months with the highest visibility are March, April, May, June, July, August, September, October and November (5mi).
The months with the lowest visibility are January, February and December (4mi).
Jamestown, Pennsylvania, USA
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