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
With December's arrival, Rochester's weather changes as the average high-temperature falls from a chilly 48.6°F (9.2°C) in November to a wintry 38.5°F (3.6°C). Nighttime temperatures consistently average a freezing cold 27.5°F (-2.5°C) during December.Humidity
In December, the average relative humidity in Rochester is 85%.Rainfall
In December, the rain falls for 11.5 days. Throughout December, 1.57" (40mm) of precipitation is accumulated. In Rochester, during the entire year, the rain falls for 168.7 days and collects up to 21.22" (539mm) of precipitation.Snowfall
January through April, October through December are months with snowfall. In Rochester, in December, during 12 snowfall days, 2.44" (62mm) of snow is typically accumulated. In Rochester, during the entire year, snow falls for 60.6 days and aggregates up to 11.93" (303mm) of snow.Daylight
With an average of 9h and 18min of daylight, December has the shortest days of the year.On the first day of December, sunrise is at 7:26 am and sunset at 4:54 pm. On the last day of the month, sunrise is at 7:44 am and sunset at 5:03 pm EST.
Sunshine
In Rochester, the average sunshine in December is 3.3h.UV index
December is the month with the lowest UV index, with an average maximum UV index of 1. A UV Index reading of 2, and below, represents a low threat to health from exposure to the Sun's UV rays for ordinary individuals.Note: A maximum high UV index of 1 in December translates into the following recommendations:
While most people can stay under the sun for an hour without burning, children must always be guarded against sun exposure. The solar radiation is most powerful near the mid-day, so the exposure to the direct Sun should be reduced accordingly. Wearing sunglasses with both UVA and UVB protection effectively reduces sun-induced eye damage. Be on the lookout! Nearly twofold UV radiation from the Sun can be reflected by 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 many days does it snow in December?
What is the month with the shortest days?
How many hours of daylight does Rochester have in December?
What time are sunrise and sunset in December?
How many hours of sunshine does Rochester have in December?
When is the lowest UV index?
What is the UV index intensity in December?
Average temperature in December
Rochester, PA
- Average high temperature in December: 38.5°F
The warmest month (with the highest average high temperature) is July (82.8°F).
The month with the lowest average high temperature is January (32.5°F).
- Average low temperature in December: 27.5°F
The month with the highest average low temperature is July (61.3°F).
The coldest month (with the lowest average low temperature) is January (19.8°F).
Average pressure in December
Rochester, PA
- Average pressure in December: 30.1"Hg
The month with the highest atmospheric pressure is November (30.13"Hg).
The month with the lowest atmospheric pressure is June (29.94"Hg).
Average wind speed in December
Rochester, PA
- Average wind speed in December: 7.4mph
The windiest month (with the highest average wind speed) is January (8.1mph).
The calmest months (with the lowest average wind speed) are July and August (4.8mph).
Average humidity in December
Rochester, PA
- Average humidity in December: 85%
The month with the highest relative humidity is February (86%).
The months with the lowest relative humidity are April, July and August (77%).
Average rainfall in December
Rochester, PA
- Average rainfall in December: 1.57"
The wettest month (with the highest rainfall) is June (2.32").
The driest month (with the least rainfall) is November (1.1").
Average rainfall days in December
Rochester, PA
- Average rainfall days in December: 11.5 days
The month with the highest number of rainy days is May (18.1 days).
The month with the least rainy days is January (10 days).
Average snowfall in December
Rochester, PA
- Average snowfall in December: 2.44"
The month with the highest snowfall is January (3.11").
The months with the least snowfall are May, June, July, August and September (0").
Average snowfall days in December
Rochester, PA
- Average snowfall days in December: 12 days
The month with the highest number of snowfall days is January (17.3 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in December /
Average sunshine in December
Rochester, 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: 2h and 54min).
Average sunshine days in December
Rochester, PA
- Average sunshine days in December: 10.6 days
The month with the most sunshine days is November (15.1 days).
The month with the least sunshine days is February (8.3 days).
Average UV index in December
Rochester, PA
- Average UV index in December: 1
The months with the highest UV index are June and July (UV index 6).
The month with the lowest UV index is December (UV index 1).
Average cloud cover in December
Rochester, PA
- Average cloud cover in December: 65
The month with the most cloud cover is January (Cloud cover 70).
The month with the least cloud cover is August (Cloud cover 34).
Average visibility in December
Rochester, PA
- Average visibility in December: 5mi
The month with the highest visibility is April (6mi).
The months with the lowest visibility are January and February (4mi).
Rochester, Pennsylvania, USA
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