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
The coldest months are January and December, with an average high-temperature of 30.9°F (-0.6°C).Humidity
The average relative humidity in December is 75%.Rainfall
The months with the least rainfall are January, November and December Rain falls for 4 days and accumulates 0.47" (12mm) of rain.Snowfall
Months with snowfall in Sumatra, Montana, are January through May, September through December. In Sumatra, in December, during 9.4 snowfall days, 2.72" (69mm) of snow is typically accumulated. In Sumatra, during the entire year, snow falls for 47 days and aggregates up to 15.83" (402mm) of snow.Daylight
December has the shortest days of the year in Sumatra, with an average of 8h and 36min of daylight.On the first day of the month, sunrise is at 7:34 am and sunset at 4:24 pm. On the last day of December, in Sumatra, sunrise is at 7:54 am and sunset at 4:32 pm MST.
Sunshine
The months with the least sunshine in Sumatra are February and December, with an average of 5.3h of sunshine.UV index
December is the month with the lowest UV index in Sumatra, Montana, with an average maximum UV index of 1. A UV Index reading of 2, and below, represents a low threat to health from exposure to the Sun's UV rays for average individuals.Note: A maximum high daily UV index of 1 during December translates into the following directions:
Most people face no serious problems with extended sun exposure, but those with fair skin, infants, and children always need protection. The Sun is at its harshest during midday; protect yourself by staying in shaded areas and minimizing exposure. In bright sunlight, prioritize sunglasses that grant protection from UVA and UVB radiation. Take careful note! The UV radiation of the Sun can be nearly doubled by snow reflection.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What are the coldest months in Sumatra?
How cold is it in Sumatra in December?
What is the average humidity in December in Sumatra?
What is the driest month in Sumatra?
How much does it rain in Sumatra in December?
How many days does it snow in December in Sumatra?
What is the month with the shortest days in Sumatra?
How many hours of daylight does Sumatra have in December?
When are sunrise and sunset in December in Sumatra?
What are the months with the least sunshine in Sumatra?
How long on average sun shines in December in Sumatra?
When is the lowest UV index in Sumatra?
What is the UV index reading in December in Sumatra?
Average temperature in December
Sumatra, MT
- Average high temperature in December: 30.9°F
The warmest month (with the highest average high temperature) is July (86.5°F).
The months with the lowest average high temperature are January and December (30.9°F).
- Average low temperature in December: 18.3°F
The month with the highest average low temperature is July (64.2°F).
The coldest month (with the lowest average low temperature) is January (17.4°F).
Average pressure in December
Sumatra, 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 (29.84"Hg).
Average wind speed in December
Sumatra, MT
- Average wind speed in December: 9.4mph
The windiest month (with the highest average wind speed) is April (10.3mph).
The calmest month (with the lowest average wind speed) is July (8.2mph).
Average humidity in December
Sumatra, MT
- Average humidity in December: 75%
The month with the highest relative humidity is January (79%).
The month with the lowest relative humidity is August (38%).
Average rainfall in December
Sumatra, MT
- Average rainfall in December: 0.47"
The wettest month (with the highest rainfall) is May (1.81").
The driest months (with the least rainfall) are January, November and December (0.47").
Average rainfall days in December
Sumatra, MT
- Average rainfall days in December: 4 days
The month with the highest number of rainy days is May (13.7 days).
The month with the least rainy days is February (3.8 days).
Average snowfall in December
Sumatra, MT
- Average snowfall in December: 2.72"
The month with the highest snowfall is February (3.74").
The months with the least snowfall are June, July and August (0").
Average snowfall days in December
Sumatra, MT
- Average snowfall days in December: 9.4 days
The month with the highest number of snowfall days is February (10.3 days).
The months with the least snowfall days are June, July and August (0 days).
Average daylight in December /
Average sunshine in December
Sumatra, 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 36min).
- Average sunshine in December: 5h and 2min
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 18min).
Average sunshine days in December
Sumatra, MT
- Average sunshine days in December: 18.6 days
The month with the most sunshine days is November (20.9 days).
The month with the least sunshine days is April (14.2 days).
Average UV index in December
Sumatra, 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
Sumatra, MT
- Average cloud cover in December: 44
The month with the most cloud cover is February (Cloud cover 46).
The months with the least cloud cover are July and August (Cloud cover 15).
Average visibility in December
Sumatra, 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).
Sumatra, Montana, USA
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