January weather forecastRoundup, MT
January
Weather in January
The city of Roundup, Montana, USA finds itself in the grip of winter during January. The weather is defined by chilly temperatures, with lows reaching 18.5°F (-7.5°C) and highs just over 31.8°F (-0.1°C). Snowfall is quite prevalent this month, marking the landscape in shades of pristine white. Days are quite short, contributing to the cool atmosphere. The frequent snow is often accompanied by bouts of rainfall turning the city into a haven for winter enthusiasts.Temperature
Roundup starts January with an average high-temperature of a still freezing cold 31.8°F (-0.1°C), a minor shift from December's 31.1°F (-0.5°C). Throughout the January nights, Roundup encounters a low-temperature of 18.5°F (-7.5°C).Humidity
January is the most humid month in Roundup, with an average relative humidity of 77%.Rainfall
January is the month with the least rainfall. Rain falls for 5.6 days and accumulates 0.55" (14mm) of precipitation.Snowfall
January through May, September through December are months with snowfall. In Roundup, Montana, during January, snow falls for 10.1 days and regularly aggregates up to 3.15" (80mm) of snow. Throughout the year, there are 53.5 snowfall days, and 18.58" (472mm) of snow is accumulated.Daylight
The average length of the day in January in Roundup is 9h and 5min.On the first day of January in Roundup, sunrise is at 7:57 am and sunset at 4:37 pm. On the last day of the month, sunrise is at 7:38 am and sunset at 5:16 pm MST.
Sunshine
The average sunshine in January in Roundup is 5.3h.UV index
The average daily maximum UV index in January in Roundup is 2. A UV Index of 2, and less, symbolizes a low threat to health from exposure to the Sun's UV radiation for ordinary individuals.Note: A maximum high UV index of 2 in January translates into 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. Being exposed to the midday Sun can have harmful effects due to strong UV radiation; always take precautions. Sunglasses providing both UVA and UVB protection are non-negotiable on sunlit days. Be alert to the fact! The reflection from snow can nearly double the UV radiation of the Sun.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in January
Roundup, MT
- Average high temperature in January: 31.8°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 January: 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 January
Roundup, MT
- Average pressure in January: 30.13"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 January
Roundup, MT
- Average wind speed in January: 11.2mph
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 January
Roundup, MT
- Average humidity in January: 77%
The month with the highest relative humidity is January (77%).
The month with the lowest relative humidity is August (39%).
Average rainfall in January
Roundup, MT
- Average rainfall in January: 0.55"
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 January
Roundup, MT
- Average rainfall days in January: 5.6 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 January
Roundup, MT
- Average snowfall in January: 3.15"
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 January
Roundup, MT
- Average snowfall days in January: 10.1 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 January /
Average sunshine in January
Roundup, MT
- Average daylight in January: 9h and 6min
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 January: 5h and 18min
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 January
Roundup, MT
- Average sunshine days in January: 18.4 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 January
Roundup, MT
- Average UV index in January: 2
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 January
Roundup, MT
- Average cloud cover in January: 44
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 January
Roundup, MT
- Average visibility in January: 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).





