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 sea temperature 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
December
Weather in December
Temperature
During the transition into December, Rochester observes a decrease in the average high-temperature, falling from a frosty 45.9°F (7.7°C) in November to a cold 36°F (2.2°C). An average low-temperature of 27.5°F (-2.5°C) is witnessed throughout the month of December, a mere drop from the daytime peak.Humidity
In Rochester, the average relative humidity in December is 83%.Rainfall
In Rochester, in December, it is raining for 11.5 days, with typically 2.48" (63mm) of accumulated precipitation. Throughout the year, there are 172.4 rainfall days, and 29.45" (748mm) of precipitation is accumulated.Snowfall
January through May, October through December are months with snowfall. In Rochester, in December, during 14.2 snowfall days, 5.31" (135mm) of snow is typically accumulated. Throughout the year, there are 70.9 snowfall days, and 27.44" (697mm) of snow is accumulated.Ocean temperature
In December, the average ocean temperature is 41.7°F (5.4°C).Note: It is advised against swimming in 41.7°F (5.4°C) when it drops below 50°F (10°C). Such temperatures can cause extreme cold shock, leading to hyperventilation.
Daylight
The month with the shortest days is December, with an average of 9h and 6min of daylight.On the first day of the month, sunrise is at 7:23 am and sunset at 4:36 pm. On the last day of December, in Rochester, sunrise is at 7:42 am and sunset at 4:45 pm EST.
Sunshine
In Rochester, the average sunshine in December is 3.1h.UV index
The months with the lowest UV index are January and December, with an average maximum UV index of 1. A UV Index reading of 2, and below, represents a low threat to health from unprotected exposure to Sun's UV rays for the average person.Note: A daily maximum UV index of 1 in December translates into the following instructions:
While many people can endure lengthy sun exposure, it remains imperative to safeguard babies, children, and fair-skinned individuals. Avoiding direct sunlight during midday hours helps reduce the risk from intense UV radiation. For minimizing sun-related eye damage, always choose sunglasses with UVA and UVB coverage. Notice! The UV radiation of the Sun can be intensified nearly twofold 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 water temperature in December in Rochester?
What is the month with the shortest days?
How many hours of daylight does Rochester have in December?
When 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 reading in December?
Average temperature in December
Rochester, NY
- Average high temperature in December: 36°F
The warmest month (with the highest average high temperature) is July (77.9°F).
The month with the lowest average high temperature is January (29.3°F).
- Average low temperature in December: 27.5°F
The month with the highest average low temperature is July (63°F).
The coldest month (with the lowest average low temperature) is January (19.8°F).
Average pressure in December
Rochester, NY
- Average pressure in December: 30.06"Hg
The month with the highest atmospheric pressure is November (30.09"Hg).
The month with the lowest atmospheric pressure is June (29.92"Hg).
Average wind speed in December
Rochester, NY
- Average wind speed in December: 10.7mph
The windiest month (with the highest average wind speed) is January (11.6mph).
The calmest month (with the lowest average wind speed) is July (7mph).
Average humidity in December
Rochester, NY
- Average humidity in December: 83%
The months with the highest relative humidity are January and February (84%).
The months with the lowest relative humidity are August and September (76%).
Average rainfall in December
Rochester, NY
- Average rainfall in December: 2.48"
The wettest month (with the highest rainfall) is May (2.99").
The driest month (with the least rainfall) is September (1.85").
Average rainfall days in December
Rochester, NY
- Average rainfall days in December: 11.5 days
The month with the highest number of rainy days is August (18.7 days).
The month with the least rainy days is February (7.8 days).
Average snowfall in December
Rochester, NY
- Average snowfall in December: 5.31"
The month with the highest snowfall is February (7.01").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days in December
Rochester, NY
- Average snowfall days in December: 14.2 days
The month with the highest number of snowfall days is January (17.6 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average sea temperature in December
Rochester, NY
- Average sea temperature in December: 41.7°F
The best month for swimming (with the highest average sea temperature) is August (73°F).
The coldest month (with the lowest average sea temperature) is March (35.8°F).
Average daylight in December /
Average sunshine in December
Rochester, NY
- Average daylight in December: 9h and 1min
The month with the longest days is June (Average daylight: 15h and 18min).
The month with the shortest days is December (Average daylight: 9h and 6min).
- Average sunshine in December: 3h and 1min
The month with the most sunshine is July (Average sunshine: 10h and 36min).
The months with the least sunshine are January and February (Average sunshine: 2h and 42min).
Average sunshine days in December
Rochester, NY
- Average sunshine days in December: 8.4 days
The month with the most sunshine days is September (13.9 days).
The month with the least sunshine days is February (6.7 days).
Average UV index in December
Rochester, NY
- Average UV index in December: 1
The month with the highest UV index is July (UV index 6).
The months with the lowest UV index are January and December (UV index 1).
Average cloud cover in December
Rochester, NY
- Average cloud cover in December: 69
The month with the most cloud cover is January (Cloud cover 74).
The month with the least cloud cover is August (Cloud cover 28).
Average visibility in December
Rochester, NY
- Average visibility in December: 6mi
The months with the highest visibility are March, April, May, June, July, August, September, October, November and December (6mi).
The months with the lowest visibility are January and February (5mi).