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 the onset of December, Rockville experiences a modest temperature adjustment, with the average high-temperature receding from a chilly 49.3°F (9.6°C) in November to a cold 38.7°F (3.7°C). During December, the nighttime temperature averages of 28.4°F (-2°C).Humidity
In December, the average relative humidity is 81%.Rainfall
In December, the rain falls for 8.3 days. Throughout December, 1.26" (32mm) of precipitation is accumulated. In Rockville, during the entire year, the rain falls for 138.6 days and collects up to 19.09" (485mm) of precipitation.Snowfall
January through April, October through December are months with snowfall. The month with the most snowfall in Rockville is December, when snow falls for 5.3 days and typically aggregates up to 1.69" (43mm) of snow.Daylight
The month with the shortest days in Rockville is December, with an average of 9h and 24min of daylight.On the first day of the month, sunrise is at 7:51 am and sunset at 5:24 pm. On the last day of December, sunrise is at 8:09 am and sunset at 5:34 pm EST.
Sunshine
The average sunshine in December is 4.4h.UV index
The months with the lowest UV index are January, February, November and December, with an average maximum UV index of 2. A UV Index reading of 2, and below, represents a minimal health vulnerability from unprotected exposure to Sun's UV rays for ordinary individuals.Note: The maximum daily UV index of 2 in December converts into the following recommendations:
Though the majority can handle prolonged sun exposure, it is crucial to always shield babies, children, and those with fair skin. Considering the Sun's intensity during midday, it's wise to minimize direct exposure. A wide-brimmed hat is a shield, deflecting up to 50% of harmful UV radiation from eyes. Be aware! The intensity of the Sun's UV radiation can be amplified nearly twice due to snow reflection.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
How cold is it in Rockville in December?
What is the average humidity in December in Rockville?
How many days does it rain in December in Rockville?
What is the snowiest month in Rockville?
How much does it snow in Rockville in December?
What is the month with the shortest days in Rockville?
How many hours of daylight does Rockville have in December?
What time are sunrise and sunset in December in Rockville?
How many hours of sunshine does Rockville have in December?
What are the months with the lowest UV index in Rockville?
What is the UV index reading in December in Rockville?
Average temperature in December
Rockville, IN
- Average high temperature in December: 38.7°F
The warmest month (with the highest average high temperature) is July (82°F).
The month with the lowest average high temperature is January (33.4°F).
- Average low temperature in December: 28.4°F
The month with the highest average low temperature is July (65.1°F).
The coldest month (with the lowest average low temperature) is January (21°F).
Average pressure in December
Rockville, IN
- Average pressure in December: 30.12"Hg
The month with the highest atmospheric pressure is January (30.14"Hg).
The month with the lowest atmospheric pressure is June (29.93"Hg).
Average wind speed in December
Rockville, IN
- Average wind speed in December: 9.3mph
The windiest month (with the highest average wind speed) is February (10.1mph).
The calmest months (with the lowest average wind speed) are July and August (6mph).
Average humidity in December
Rockville, IN
- Average humidity in December: 81%
The month with the highest relative humidity is July (84%).
The month with the lowest relative humidity is October (73%).
Average rainfall in December
Rockville, IN
- Average rainfall in December: 1.26"
The wettest months (with the highest rainfall) are April and May (2.52").
The driest month (with the least rainfall) is February (1.06").
Average rainfall days in December
Rockville, IN
- Average rainfall days in December: 8.3 days
The month with the highest number of rainy days is May (17.9 days).
The month with the least rainy days is February (6.9 days).
Average snowfall in December
Rockville, IN
- Average snowfall in December: 1.69"
The month with the highest snowfall is December (1.69").
The months with the least snowfall are May, June, July, August and September (0").
Average snowfall days in December
Rockville, IN
- Average snowfall days in December: 5.3 days
The month with the highest number of snowfall days is January (7.1 days).
The months with the least snowfall days are May, June, July, August and September (0 days).
Average daylight in December /
Average sunshine in December
Rockville, IN
- Average daylight in December: 9h and 2min
The month with the longest days is June (Average daylight: 14h and 54min).
The month with the shortest days is December (Average daylight: 9h and 24min).
- Average sunshine in December: 4h and 2min
The month with the most sunshine is June (Average sunshine: 10h and 12min).
The month with the least sunshine is January (Average sunshine: 4h and 18min).
Average sunshine days in December
Rockville, IN
- Average sunshine days in December: 17.7 days
The month with the most sunshine days is November (19.9 days).
The month with the least sunshine days is May (10 days).
Average UV index in December
Rockville, IN
- 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, November and December (UV index 2).
Average cloud cover in December
Rockville, IN
- Average cloud cover in December: 55
The month with the most cloud cover is January (Cloud cover 57).
The months with the least cloud cover are August and September (Cloud cover 31).
Average visibility in December
Rockville, IN
- Average visibility in December: 6mi
The months with the highest visibility are January, February, March, April, May, June, September, October, November and December (6mi).
The months with the lowest visibility are July and August (5mi).
Rockville, Indiana, USA
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