Weather in December
Temperature
The onset of December is marked by a decrease in temperature, transitioning from a frosty 48.2°F (9°C) in November to a cold 35.6°F (2°C). During the month of December, the nighttime temperature falls to an average of 21.2°F (-6°C).Rainfall
In Greater Rochester International Airport, in December, it is raining for 17 days, with typically 2.52" (64mm) of accumulated precipitation. Throughout the year, there are 152 rainfall days, and 31.89" (810mm) of precipitation is accumulated.Ocean temperature
In Greater Rochester International Airport, the average seawater temperature in December is 41°F (5°C).Note: While a brief time in 41°F (5°C) at 55.4°F (13°C) is already bracing, plunging below 50°F (10°C) can severely affect breathing and introduce a cold shock, relying on your physical state.
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, sunrise is at 7:42 am and sunset at 4:45 pm EST.
Sunshine
The months with the least sunshine are January, November and December, with an average of 3h of sunshine.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 threat to health from exposure to the Sun's UV rays for ordinary individuals.Note: The maximum UV index, 1 during December, leads to the following recommendations:
In contrast to children, who must always be shielded from the sun, most people can tolerate up to an hour of sun exposure without any burns. Direct Sun exposure should be minimized especially during midday when radiation is most intense. Safeguard your eyes, ears, and face from sun rays with the aid of a wide-brim hat.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
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Average temperature in December
Greater Rochester International Airport, NY
- Average high temperature in December: 36°F
The warmest month (with the highest average high temperature) is July (81°F).
The month with the lowest average high temperature is January (30°F).
- Average low temperature in December: 21°F
The months with the highest average low temperature are July and August (59°F).
The coldest months (with the lowest average low temperature) are January and February (16°F).
Average rainfall in December
Greater Rochester International Airport, NY
- Average rainfall in December: 2.5"
The wettest month (with the highest rainfall) is August (3.3").
The driest months (with the least rainfall) are January and February (2").
Average rainfall days in December
Greater Rochester International Airport, NY
- Average rainfall days in December: 17 days
The month with the highest number of rainy days is December (17 days).
The month with the least rainy days is July (9 days).
Average sea temperature in December
Greater Rochester International Airport, NY
- Average sea temperature in December: 41°F
The best month for swimming (with the highest average sea temperature) is August (70°F).
The coldest months (with the lowest average sea temperature) are February and March (36°F).
Average daylight in December /
Average sunshine in December
Greater Rochester International Airport, 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
The months with the most sunshine are June and July (Average sunshine: 10h).
The months with the least sunshine are January, November and December (Average sunshine: 3h).
Average UV index in December
Greater Rochester International Airport, NY
- Average UV index in December: 1
The months with the highest UV index are June and July (UV index 8).
The months with the lowest UV index are January and December (UV index 1).
Greater Rochester International Airport, New York, USA
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