December weather forecastRochester, MA
December
Weather in December
The first month of the winter, December, is also a wintry month in Rochester, Massachusetts, with an average temperature ranging between max 42.3°F (5.7°C) and min 33.6°F (0.9°C).Temperature
During the shift to December, Rochester records a mild decrease in average high-temperature, moving from a fresh 50.9°F (10.5°C) in November to a cold 42.3°F (5.7°C). During the month of December, Rochester identifies an average nighttime low-temperature of 33.6°F (0.9°C), slightly lower than its daytime counterpart.Humidity
The average relative humidity in December is 76%.Rainfall
In Rochester, during December, the rain falls for 10.3 days and regularly aggregates up to 1.5" (38mm) of precipitation. Throughout the year, there are 136.3 rainfall days, and 15.63" (397mm) of precipitation is accumulated.Snowfall
January through May, October through December are months with snowfall. In December, it is snowing for 3.2 days. Throughout December, 0.75" (19mm) of snow is accumulated. Throughout the year, there are 21.6 snowfall days, and 4.29" (109mm) of snow is accumulated.Daylight
The month with the shortest days is December, with an average of 9h and 12min of daylight.On the first day of the month, sunrise is at 6:51 am and sunset at 4:13 pm. On the last day of December, sunrise is at 7:10 am and sunset at 4:22 pm EST.
Sunshine
In Rochester, Massachusetts, the average sunshine in December is 4.9h.UV index
January through March, November and December, with an average maximum UV index of 2, are months with the lowest UV index. A UV Index of 2, and less, symbolizes a low health risk from unsafe exposure to UV radiation for average individuals.Note: The maximum daily UV index of 2 in December interprets into the following recommendations:
Though extended exposure to the sun typically does not concern most people, it is crucial to always shield children, infants, and those with sensitive skin. Exposing oneself to the midday Sun can be harmful due to the strong UV radiation; limit your time outside. Consider a wide-brim hat essential for effective sun defense covering your face, neck, and eyes. Take heed! Reflection from the snow can almost amplify the Sun's UV radiation by double.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in December
Rochester, MA
- Average high temperature in December: 42.3°F
The warmest month (with the highest average high temperature) is August (76.6°F).
The month with the lowest average high temperature is January (36.7°F).
- Average low temperature in December: 33.6°F
The month with the highest average low temperature is August (66.7°F).
The coldest month (with the lowest average low temperature) is January (27.3°F).
Average pressure in December
Rochester, MA
- Average pressure in December: 30.03"Hg
The month with the highest atmospheric pressure is November (30.06"Hg).
The month with the lowest atmospheric pressure is June (29.93"Hg).
Average wind speed in December
Rochester, MA
- Average wind speed in December: 12.3mph
The windiest month (with the highest average wind speed) is January (12.9mph).
The calmest month (with the lowest average wind speed) is August (8.3mph).
Average humidity in December
Rochester, MA
- Average humidity in December: 76%
The months with the highest relative humidity are June and July (80%).
The months with the lowest relative humidity are March and November (74%).
Average rainfall in December
Rochester, MA
- Average rainfall in December: 1.5"
The wettest month (with the highest rainfall) is October (1.89").
The driest month (with the least rainfall) is February (0.98").
Average rainfall days in December
Rochester, MA
- Average rainfall days in December: 10.3 days
The months with the highest number of rainy days are May and July (14.1 days).
The month with the least rainy days is February (7.7 days).
Average snowfall in December
Rochester, MA
- Average snowfall in December: 0.75"
The month with the highest snowfall is February (1.1").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days in December
Rochester, MA
- Average snowfall days in December: 3.2 days
The month with the highest number of snowfall days is January (6.6 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, MA
- Average daylight in December: 9h and 12min
The month with the longest days is June (Average daylight: 15h and 12min).
The month with the shortest days is December (Average daylight: 9h and 12min).
- Average sunshine in December: 4h and 54min
The month with the most sunshine is August (Average sunshine: 10h and 42min).
The month with the least sunshine is February (Average sunshine: 4h and 48min).
Average sunshine days in December
Rochester, MA
- Average sunshine days in December: 17.7 days
The month with the most sunshine days is December (17.7 days).
The month with the least sunshine days is April (14.3 days).
Average UV index in December
Rochester, MA
- Average UV index in December: 2
The months with the highest UV index are June, July and August (UV index 6).
The months with the lowest UV index are January, February, March, November and December (UV index 2).
Average cloud cover in December
Rochester, MA
- Average cloud cover in December: 48
The month with the most cloud cover is March (Cloud cover 49).
The month with the least cloud cover is August (Cloud cover 28).
Average visibility in December
Rochester, MA
- Average visibility in December: 6mi
The months with the highest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).
The months with the lowest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).
