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
December in Roy comes with a drop in the average high-temperature, falling from November's chilly 45.5°F (7.5°C) to an icy 34°F (1.1°C). In December, Roy records an average nighttime temperature of 23.4°F (-4.8°C).Humidity
In December, the average relative humidity is 77%.Rainfall
In Roy, during December, the rain falls for 5.5 days and regularly aggregates up to 1.02" (26mm) of precipitation. In Roy, during the entire year, the rain falls for 91.6 days and collects up to 11.06" (281mm) of precipitation.Snowfall
January through May, September through December are months with snowfall. In December, it is snowing for 8.2 days. Throughout December, 4.37" (111mm) of snow is accumulated. In Roy, during the entire year, snow falls for 37.8 days and aggregates up to 24.76" (629mm) of snow.Daylight
December has the shortest days of the year, with an average of 9h and 18min of daylight.On the first day of the month, sunrise is at 7:34 am and sunset at 5:00 pm. On the last day of December, sunrise is at 7:53 am and sunset at 5:09 pm MST.
Sunshine
In December, the average sunshine is 6h.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 value of 2, and less, symbolizes a minimal health hazard from exposure to the Sun's UV radiation for ordinary individuals.Note: A typical high UV index of 2 in December suggests the following recommendations:
Extended sunlight exposure does not pose significant problems for most people, except for children, infants, and people with fair skin who always need shielding. The Sun's most intense and consequently most harmful UV radiation during midday hours should be decreased by minimizing exposure and seeking shade. Your best bet for sun defense on the face, eyes, and neck is a hat with a wide brim. Take note! UV radiation from the Sun can double in intensity due to snow reflection.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
How cold is it in December?
What is the average humidity in December?
How much does it rain in Roy in December?
How much does it snow in December?
What is the month with the shortest days?
What is the average length of the day in December?
When is the sunrise / sunset in December in Roy?
How long on average sun shines in December?
When is the lowest UV index in Roy?
What is the UV index reading in December?
Average temperature in December
Roy, UT
- Average high temperature in December: 34°F
The warmest month (with the highest average high temperature) is July (83.8°F).
The month with the lowest average high temperature is January (33.4°F).
- Average low temperature in December: 23.4°F
The month with the highest average low temperature is July (60.4°F).
The coldest month (with the lowest average low temperature) is January (21.6°F).
Average pressure in December
Roy, UT
- Average pressure in December: 30.23"Hg
The month with the highest atmospheric pressure is January (30.29"Hg).
The month with the lowest atmospheric pressure is June (29.88"Hg).
Average wind speed in December
Roy, UT
- Average wind speed in December: 5.5mph
The windiest month (with the highest average wind speed) is April (6.5mph).
The calmest month (with the lowest average wind speed) is January (4.8mph).
Average humidity in December
Roy, UT
- Average humidity in December: 77%
The month with the highest relative humidity is January (83%).
The month with the lowest relative humidity is July (37%).
Average rainfall in December
Roy, UT
- Average rainfall in December: 1.02"
The wettest month (with the highest rainfall) is April (1.26").
The driest month (with the least rainfall) is July (0.43").
Average rainfall days in December
Roy, UT
- Average rainfall days in December: 5.5 days
The month with the highest number of rainy days is May (12.5 days).
The month with the least rainy days is January (4.6 days).
Average snowfall in December
Roy, UT
- Average snowfall in December: 4.37"
The month with the highest snowfall is January (6.89").
The months with the least snowfall are June, July and August (0").
Average snowfall days in December
Roy, UT
- Average snowfall days in December: 8.2 days
The month with the highest number of snowfall days is January (8.8 days).
The months with the least snowfall days are June, July and August (0 days).
Average daylight in December /
Average sunshine in December
Roy, UT
- Average daylight in December: 9h and 2min
The month with the longest days is June (Average daylight: 15h and 6min).
The month with the shortest days is December (Average daylight: 9h and 18min).
- Average sunshine in December: 6h and 0min
The months with the most sunshine are June, July and August (Average sunshine: 11h and 54min).
The month with the least sunshine is January (Average sunshine: 5h and 36min).
Average sunshine days in December
Roy, UT
- Average sunshine days in December: 19.9 days
The months with the most sunshine days are October and November (21.6 days).
The month with the least sunshine days is April (14.7 days).
Average UV index in December
Roy, UT
- 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
Roy, UT
- Average cloud cover in December: 37
The months with the most cloud cover are January and February (Cloud cover 40).
The month with the least cloud cover is August (Cloud cover 10).
Average visibility in December
Roy, UT
- Average visibility in December: 6mi
The months with the highest visibility are February, March, April, May, June, July, August, September, October, November and December (6mi).
The month with the lowest visibility is January (5mi).
Roy, Utah, USA
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