January weather forecast
Boulder, WY

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Weather in January

Kickstarting the year, Boulder's weather in January tends to be severe due to frigid temperatures and higher frequency of snowfall. A low temperature could drop to 5.4°F (-14.8°C), making it one of the coldest months of the year. Sunlight is limited, and the city is often shrouded in clouds, contributing to the overall cold season. Residents can expect an increased likelihood of snow, necessitating warm clothing and heating methods. Furthermore, brisk winds often accompany the falling snow, adding an additional chill.

Temperature

The arrival of January brings an average high-temperature of a still freezing cold 25.2°F (-3.8°C), nearly identical to December's 23.9°F (-4.5°C). Throughout the month of January, Boulder expects an average low of 5.4°F (-14.8°C).

Humidity

In January, the average relative humidity is 85%.

Rainfall

In January, in Boulder, the rain falls for 5.5 days. Throughout January, 0.63" (16mm) of precipitation is accumulated. Throughout the year, there are 102.6 rainfall days, and 10.75" (273mm) of precipitation is accumulated.

Snowfall

January through June, September through December are months with snowfall in Boulder. In Boulder, in January, during 10.2 snowfall days, 5.08" (129mm) of snow is typically accumulated. In Boulder, during the entire year, snow falls for 86.8 days and aggregates up to 41.77" (1061mm) of snow.

Daylight

The average length of the day in January is 9h and 28min.
On the first day of January, sunrise is at 7:49 am and sunset at 4:55 pm. On the last day of the month, sunrise is at 7:34 am and sunset at 5:30 pm MST.

Sunshine

January has the least sunshine of the year, with an average of 6.3h of sunshine.

UV index

January through April, October through December, with an average maximum UV index of 2, are months with the lowest UV index. A UV Index reading of 2, and below, represents a low threat to health from unprotected exposure to Sun's UV rays for the ordinary person.
Note: The UV index of 2 during January leads to these advisories:
Though the majority can handle prolonged sun exposure, it is crucial to always shield babies, children, and those with fair skin. Direct exposure to the Sun's intense radiation around midday should be avoided for health reasons. A wide-brimmed hat is a shield, deflecting up to 50% of harmful UV radiation from eyes. Take warning! The intensity of the Sun's UV radiation can be nearly amplified twice due to snow reflection.
Updated: Feb 14, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

How cold is January in Boulder?

An average high-temperature, in January, in Boulder, is 25.2°F (-3.8°C) and the average low-temperature is 5.4°F (-14.8°C).

What is the average humidity in January in Boulder?

The average relative humidity in January is 85%.

How many days does it rain in January in Boulder?

In Boulder, Wyoming, in January, during 5.5 rainfall days, 0.63" (16mm) of precipitation is typically accumulated.

How many days does it snow in January in Boulder?

In Boulder, in January, snow falls for 10.2 days, with typically accumulated 5.08" (129mm) of snow.

What is the average length of the day in January in Boulder?

In Boulder, the average day length in January is 9h and 28min.

What time are sunrise and sunset in January in Boulder?

In January, on the first day of the month, sunrise is at 7:49 am and sunset at 4:55 pm. On the last day of the month, sunrise is at 7:34 am and sunset at 5:30 pm MST.

What is the month with the least sunshine in Boulder?

The month with the least sunshine in Boulder, Wyoming, is January, with an average of 6.3h of sunshine.

How many hours of sunshine does Boulder have in January?

In January, the average sunshine duration in Boulder, Wyoming, is 6.3h.

When is the lowest UV index in Boulder?

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

What is the UV index reading in January in Boulder?

In January, the average daily maximum UV index in Boulder, Wyoming, is 2. A UV Index estimate of 2, and below, represents a minimal hazard to health from exposure to the Sun's UV radiation.
Average humidity
Average rainfall days
Average snowfall days
Average daylight
Average sunshine
Average sunshine days
Average UV index
Average cloud cover
Average visibility

Average temperature in January
Boulder, WY

Average temperature in January - Boulder, WY
  • Average high temperature in January: 25.2°F

The warmest month (with the highest average high temperature) is July (78.4°F).
The month with the lowest average high temperature is December (23.9°F).

  • Average low temperature in January: 5.4°F

The month with the highest average low temperature is July (55.2°F).
The coldest month (with the lowest average low temperature) is January (5.4°F).

Average pressure in January
Boulder, WY

Average pressure in January - Boulder, WY
  • Average pressure in January: 30.27"Hg

The month with the highest atmospheric pressure is January (30.27"Hg).
The month with the lowest atmospheric pressure is June (29.9"Hg).

Average wind speed in January
Boulder, WY

Average wind speed in January - Boulder, WY
  • Average wind speed in January: 6.1mph

The windiest month (with the highest average wind speed) is June (8.1mph).
The calmest month (with the lowest average wind speed) is December (5.8mph).

Average humidity in January
Boulder, WY

Average humidity in January - Boulder, WY
  • Average humidity in January: 85%

The month with the highest relative humidity is February (86%).
The month with the lowest relative humidity is August (34%).

Average rainfall in January
Boulder, WY

Average rainfall in January - Boulder, WY
  • Average rainfall in January: 0.63"

The wettest month (with the highest rainfall) is May (1.73").
The driest month (with the least rainfall) is August (0.51").

Average rainfall days in January
Boulder, WY

Average rainfall days in January - Boulder, WY
  • Average rainfall days in January: 5.5 days

The month with the highest number of rainy days is May (15.2 days).
The month with the least rainy days is January (5.5 days).

Average snowfall in January
Boulder, WY

Average snowfall in January - Boulder, WY
  • Average snowfall in January: 5.08"

The month with the highest snowfall is February (7.32").
The months with the least snowfall are July and August (0").

Average snowfall days in January
Boulder, WY

Average snowfall days in January - Boulder, WY
  • Average snowfall days in January: 10.2 days

The month with the highest number of snowfall days is March (15.7 days).
The months with the least snowfall days are July and August (0 days).

Average daylight in January /
Average sunshine in January
Boulder, WY

Average daylight in January / Average sunshine in January - Boulder, WY
  • Average daylight in January: 9h and 3min

The month with the longest days is June (Average daylight: 15h and 18min).
The month with the shortest days is December (Average daylight: 9h and 6min).

  • Average sunshine in January: 6h and 2min

The months with the most sunshine are July and August (Average sunshine: 11h and 54min).
The month with the least sunshine is January (Average sunshine: 6h and 18min).

Average sunshine days in January
Boulder, WY

Average sunshine days in January - Boulder, WY
  • Average sunshine days in January: 19.8 days

The month with the most sunshine days is January (19.8 days).
The month with the least sunshine days is May (9.7 days).

Average UV index in January
Boulder, WY

Average UV index in January - Boulder, WY
  • Average UV index in January: 2

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

Average cloud cover in January
Boulder, WY

Average cloud cover in January - Boulder, WY
  • Average cloud cover in January: 34

The month with the most cloud cover is February (Cloud cover 39).
The month with the least cloud cover is August (Cloud cover 11).

Average visibility in January
Boulder, WY

Average visibility in January - Boulder, WY
  • Average visibility in January: 4mi

The months with the highest visibility are April, May, June, July, August, September, October and November (6mi).
The months with the lowest visibility are January and February (4mi).

Boulder, Wyoming, USA

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