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
Saint Marys's December weather shows a moderate shift in high-temperatures, falling from November's chilly 44.4°F (6.9°C) to an icy 34.7°F (1.5°C). The low-temperature average for Saint Marys during December stands at a subzero cold 25°F (-3.9°C).Humidity
In December, the average relative humidity in Saint Marys is 87%.Rainfall
In Saint Marys, Pennsylvania, during December, the rain falls for 7.5 days and regularly aggregates up to 1.06" (27mm) of precipitation. In Saint Marys, during the entire year, the rain falls for 118.9 days and collects up to 13.31" (338mm) of precipitation.Snowfall
Months with snowfall are January through May, October through December. In Saint Marys, in December, snow falls for 10.2 days, with typically accumulated 2.6" (66mm) of snow. In Saint Marys, during the entire year, snow falls for 52.7 days and aggregates up to 16.14" (410mm) of snow.Daylight
The month with the shortest days in Saint Marys is December, with an average of 9h and 12min of daylight.On the first day of December, sunrise is at 7:21 am and sunset at 4:45 pm. On the last day of the month, sunrise is at 7:40 am and sunset at 4:54 pm EST.
Sunshine
In December, the average sunshine is 2.6h.UV index
January 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 unprotected exposure to Sun's UV rays for ordinary individuals.Note: An average maximum UV index of 1 in December leads to these recommendations:
The majority are not significantly affected by prolonged sun exposure. Infants, children, and those with fair skin must always have protection. For skin protection, it's recommended to minimize Sun exposure during its peak hours around midday. Boost your sun resistance with garments that are densely woven yet spacious. Bear in mind! The Sun's UV radiation can nearly double in intensity due to the reflective quality of snow.
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 Saint Marys have in December?
What time are sunrise and sunset in December in Saint Marys?
How long on average sun shines in December in Saint Marys?
When is the lowest UV index?
How high is the UV index in December?
Average temperature in December
Saint Marys, PA
- Average high temperature in December: 34.7°F
The warmest month (with the highest average high temperature) is July (79.3°F).
The month with the lowest average high temperature is January (28.8°F).
- Average low temperature in December: 25°F
The month with the highest average low temperature is July (57.2°F).
The coldest month (with the lowest average low temperature) is January (16.3°F).
Average pressure in December
Saint Marys, PA
- Average pressure in December: 30.09"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
Saint Marys, PA
- Average wind speed in December: 8.3mph
The windiest month (with the highest average wind speed) is January (8.9mph).
The calmest month (with the lowest average wind speed) is August (5.5mph).
Average humidity in December
Saint Marys, PA
- Average humidity in December: 87%
The month with the highest relative humidity is February (89%).
The months with the lowest relative humidity are June and July (78%).
Average rainfall in December
Saint Marys, PA
- Average rainfall in December: 1.06"
The wettest month (with the highest rainfall) is April (1.5").
The driest months (with the least rainfall) are January and November (0.83").
Average rainfall days in December
Saint Marys, PA
- Average rainfall days in December: 7.5 days
The month with the highest number of rainy days is May (15.7 days).
The month with the least rainy days is February (5.1 days).
Average snowfall in December
Saint Marys, PA
- Average snowfall in December: 2.6"
The month with the highest snowfall is February (4.21").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days in December
Saint Marys, PA
- Average snowfall days in December: 10.2 days
The month with the highest number of snowfall days is January (12.2 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in December /
Average sunshine in December
Saint Marys, 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 4min
The months with the most sunshine are July and August (Average sunshine: 9h and 30min).
The month with the least sunshine is January (Average sunshine: 2h and 30min).
Average sunshine days in December
Saint Marys, PA
- Average sunshine days in December: 16.5 days
The month with the most sunshine days is November (18.9 days).
The month with the least sunshine days is May (13 days).
Average UV index in December
Saint Marys, PA
- Average UV index in December: 1
The months with the highest UV index are May, June, July and August (UV index 5).
The months with the lowest UV index are January and December (UV index 1).
Average cloud cover in December
Saint Marys, PA
- Average cloud cover in December: 75
The month with the most cloud cover is January (Cloud cover 77).
The month with the least cloud cover is July (Cloud cover 42).
Average visibility in December
Saint Marys, PA
- Average visibility in December: 5mi
The months with the highest visibility are January, February, March, April, May, June, July, October, November and December (5mi).
The months with the lowest visibility are August and September (4mi).
Saint Marys, Pennsylvania, USA
Weather forecast for your location
2. Allow the app to use your location