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
In Roundup, December is the month with the lowest recorded average temperatures, measuring a high of 31.1°F (-0.5°C) and a low of 18.5°F (-7.5°C).Humidity
In December, the average relative humidity is 74%.Rainfall
In Roundup, during December, the rain falls for 5.5 days and regularly aggregates up to 0.59" (15mm) of precipitation. In Roundup, during the entire year, the rain falls for 114.3 days and collects up to 12.13" (308mm) of precipitation.Snowfall
January through May, September through December are months with snowfall in Roundup. In Roundup, in December, snow falls for 9.6 days, with typically accumulated 2.72" (69mm) of snow. In Roundup, Montana, during the entire year, snow falls for 53.5 days and aggregates up to 18.58" (472mm) of snow.Daylight
December has the shortest days of the year in Roundup, Montana, with an average of 8h and 42min of daylight.On the first day of the month, sunrise is at 7:37 am and sunset at 4:28 pm. On the last day of December, in Roundup, Montana, sunrise is at 7:57 am and sunset at 4:37 pm MST.
Sunshine
February and December, with an average of 5.2h of sunshine, are months with the least sunshine in Roundup.UV index
December is the month with the lowest UV index, with an average maximum UV index of 1. A UV Index value of 2, and less, symbolizes a minimal health vulnerability from unprotected exposure to Sun's UV rays for average individuals.Note: A daily high UV index of 1 in December leads to these guidelines:
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. When the Sun's UV radiation is most intense during midday, it's best to find shade and limit exposure. Protect your eyes, ears, face, and neck from the Sun by wearing a wide-brimmed hat. Be informed! The Sun's UV radiation can be nearly doubled due to the reflection from snow.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What part of the year is the coldest in Roundup?
How cold is December in Roundup?
What is the average humidity in December in Roundup?
How much does it rain in Roundup in December?
How many days does it snow in December in Roundup?
What is the month with the shortest days in Roundup?
What is the average length of the day in December in Roundup?
When are sunrise and sunset in December in Roundup?
What are the months with the least sunshine in Roundup?
How long on average sun shines in December in Roundup?
What is the month with the lowest UV index in Roundup?
What is the UV index intensity in December in Roundup?
Average temperature in December
Roundup, MT
- Average high temperature in December: 31.1°F
The warmest month (with the highest average high temperature) is July (84.7°F).
The month with the lowest average high temperature is December (31.1°F).
- Average low temperature in December: 18.5°F
The month with the highest average low temperature is July (62.4°F).
The coldest month (with the lowest average low temperature) is February (18°F).
Average pressure in December
Roundup, MT
- Average pressure in December: 30.12"Hg
The month with the highest atmospheric pressure is January (30.13"Hg).
The month with the lowest atmospheric pressure is June (29.85"Hg).
Average wind speed in December
Roundup, MT
- Average wind speed in December: 11mph
The windiest month (with the highest average wind speed) is January (11.2mph).
The calmest months (with the lowest average wind speed) are July and August (8.5mph).
Average humidity in December
Roundup, MT
- Average humidity in December: 74%
The month with the highest relative humidity is January (77%).
The month with the lowest relative humidity is August (39%).
Average rainfall in December
Roundup, MT
- Average rainfall in December: 0.59"
The wettest month (with the highest rainfall) is May (1.97").
The driest month (with the least rainfall) is January (0.55").
Average rainfall days in December
Roundup, MT
- Average rainfall days in December: 5.5 days
The month with the highest number of rainy days is May (15.6 days).
The month with the least rainy days is February (4.6 days).
Average snowfall in December
Roundup, MT
- Average snowfall in December: 2.72"
The month with the highest snowfall is February (3.78").
The months with the least snowfall are June, July and August (0").
Average snowfall days in December
Roundup, MT
- Average snowfall days in December: 9.6 days
The month with the highest number of snowfall days is February (11.1 days).
The months with the least snowfall days are June, July and August (0 days).
Average daylight in December /
Average sunshine in December
Roundup, MT
- Average daylight in December: 8h and 4min
The month with the longest days is June (Average daylight: 15h and 48min).
The month with the shortest days is December (Average daylight: 8h and 42min).
- Average sunshine in December: 5h and 1min
The month with the most sunshine is July (Average sunshine: 11h and 48min).
The months with the least sunshine are February and December (Average sunshine: 5h and 12min).
Average sunshine days in December
Roundup, MT
- Average sunshine days in December: 17.8 days
The month with the most sunshine days is September (19.5 days).
The month with the least sunshine days is April (12.8 days).
Average UV index in December
Roundup, MT
- Average UV index in December: 1
The month with the highest UV index is July (UV index 7).
The month with the lowest UV index is December (UV index 1).
Average cloud cover in December
Roundup, MT
- Average cloud cover in December: 45
The month with the most cloud cover is February (Cloud cover 47).
The months with the least cloud cover are July and August (Cloud cover 16).
Average visibility in December
Roundup, MT
- 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).
Roundup, Montana, USA
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