January weather forecast and climate
Roy, MT

January, like December, is a freezing cold winter month in Roy, Montana, with average temperature fluctuating between 16.9°F (-8.4°C) and 30.6°F (-0.8°C).

Temperature

In Roy, Montana, the average high-temperature is essentially the same as in December - a still subzero cold 30.6°F (-0.8°C). In Roy, the average low-temperature is 16.9°F (-8.4°C).

Humidity

In Roy, the average relative humidity is 78%.

Rainfall

In January, the rain falls for 5.4 days. Throughout January, 0.83" (21mm) of precipitation is accumulated. In Roy, during the entire year, the rain falls for 126.2 days and collects up to 17.83" (453mm) of precipitation.

Snowfall

January through June, September through December are months with snowfall in Roy. In Roy, Montana, snow falls for 12.9 days, with typically accumulated 5.47" (139mm) of snow. In Roy, during the entire year, snow falls for 83.4 days, and aggregates up to 45.51" (1156mm) of snow.

Daylight

In Roy, the average length of the day is 9h.

Sunshine

In Roy, the average sunshine is 5.7h.

UV index

January through April, October through December, with an average maximum UV index of 2, are months with the lowest UV index in Roy. A UV Index estimate of 2, and below, represents a minimal health vulnerability from unprotected exposure to the Sun's UV rays for average individuals.
Note: In January, the average maximum UV index of 2 translate into the following recommendations:
Most people can stay in the Sun for up to 1 hour without burning, apart from children that always must be protected from sun exposure. The solar radiation is most powerful near the mid-day, so the exposure to the direct Sun should be reduced accordingly. A wide-brim hat offers excellent sun protection for eyes, ears, face, and neck. Sunglasses with UVA and UVB protection significantly reduce eye damage from sun exposure. Tightly woven, loose-fitting clothes provide additional protection from the Sun. Caution! The reflection of snow can nearly double the intensity of the Sun's UV radiation.

What is the temperature in January in Roy?

In January, in Roy, the average high-temperature is 30.6°F (-0.8°C), and the average low-temperature is 16.9°F (-8.4°C).

What is the average humidity in January in Roy?

The average relative humidity in January is 78%.

How many days does it rain in January in Roy?

In Roy, in January, during 5.4 rainfall days, 0.83" (21mm) of precipitation is typically accumulated.

How many days does it snow in January in Roy?

In Roy, Montana, during January, snow falls for 12.9 days and regularly aggregates up to 5.47" (139mm) of snow.

How many hours of daylight does Roy have in January?

In January, the average length of the day is 9h.

How many hours of sunshine does Roy have in January?

In Roy, the average sunshine in January is 5.7h.

What is the month with the lowest UV index in Roy?

January through April, October through December, with an average maximum UV index of 2, are months with the lowest UV index in Roy, Montana.

What is the UV index reading in January in Roy?

The average daily maximum UV index in January in Roy is 2. A UV Index reading of 2, and below, represents a minimal health vulnerability from unprotected exposure to the UV radiation.
Average temperature in January - Roy, MT
  • Average high temperature in January: -0.8°C

The warmest month (with the highest average high temperature) is July (26°C).
Months with the lowest average high temperature are February and December (-1.6°C).

  • Average low temperature in January: -8.4°C

The month with the highest average low temperature is August (12.5°C).
The coldest month (with the lowest average low temperature) is February (-9.3°C).

Average pressure in January - Roy, MT
  • Average pressure in January: 1020.3mbar

The month with the highest atmospheric pressure is January (1020.3mbar).
The month with the lowest atmospheric pressure is June (1010.9mbar).

Average wind speed in January - Roy, MT
  • Average wind speed in January: 15.9km/h

The windiest months (with the highest average wind speed) are January, April and October (15.9km/h).
The calmest month (with the lowest average wind speed) is August (11.9km/h).

Average humidity in January - Roy, MT
  • Average humidity in January: 78%

The month with the highest relative humidity is February (79%).
The month with the lowest relative humidity is August (47%).

Average rainfall in January - Roy, MT
  • Average rainfall in January: 21mm

The wettest month (with the highest rainfall) is May (86mm).
The driest month (with the least rainfall) is December (18mm).

Average rainfall days in January - Roy, MT
  • Average rainfall days in January: 5.4 days

The month with the highest number of rainy days is May (19.3 days).
The month with the least rainy days is January (5.4 days).

Average snowfall in January - Roy, MT
  • Average snowfall in January: 139mm

The month with the highest snowfall is April (232mm).
Months with the least snowfall are July and August (0mm).

Average snowfall days in January - Roy, MT
  • Average snowfall days in January: 12.9 days

The month with the highest number of snowfall days is February (15.2 days).
Months with the least snowfall days are July and August (0 days).

Average daylight in January / Average sunshine in January - Roy, MT
  • Average daylight in January: 9h

The month with the longest days is June (Average daylight: 15.9h).
The month with the shortest days is December (Average daylight: 8.5h).

  • Average sunshine in January: 5.7h

The month with the most sunshine is July (Average sunshine: 11.8h).
The month with the least sunshine is February (Average sunshine: 5.5h).

Average sunshine days in January - Roy, MT
  • Average sunshine days in January: 15.9 days

The month with the most sunshine days is September (19.3 days).
The month with the least sunshine days is April (8.3 days).

Average UV index in January - Roy, MT
  • Average UV index in January: 2

The month with the highest UV index is July (UV index 6).
Months with the lowest UV index are January, February, March, April, October, November and December (UV index 2).

Average cloud cover in January - Roy, MT
  • Average cloud cover in January: 39

The month with the most cloud cover is February (Cloud cover 45).
The month with the least cloud cover is July (Cloud cover 16).

Average visibility in January - Roy, MT
  • Average visibility in January: 9km

Months with the highest visibility are June, July, August and September (10km).
Months with the lowest visibility are January, February, March, April, May, October, November and December (9km).