Contents
- Weather in January
- Frequently asked questions
- Average temperature in January
- Average pressure in January
- Average wind speed in January
- Average humidity in January
- Average rainfall in January
- Average rainfall days in January
- Average snowfall in January
- Average snowfall days in January
- Average daylight in January
- Average sunshine in January
- Average sunshine days in January
- Average UV index in January
- Average cloud cover in January
- Average visibility in January
Weather in January
Temperature
The arrival of January brings an average high-temperature of a still icy 36.7°F (2.6°C), nearly identical to December's 35.2°F (1.8°C). In January, Boulder encounters an average low-temperature of 19°F (-7.2°C) during the night.Humidity
The average relative humidity in January is 68%.Rainfall
The month with the least rainfall is January, when the rain falls for 4.3 days and typically collects 0.39" (10mm) of precipitation.Snowfall
January through May, October through December are months with snowfall. In Boulder, during January, snow falls for 6.3 days and regularly aggregates up to 2.87" (73mm) of snow. In Boulder, during the entire year, snow falls for 44.8 days and aggregates up to 37.01" (940mm) of snow.Daylight
In January, the average length of the day is 9h and 43min.On the first day of January in Boulder, sunrise is at 7:22 am and sunset at 4:46 pm. On the last day of the month, sunrise is at 7:10 am and sunset at 5:18 pm MST.
Sunshine
In Boulder, the average sunshine in January is 6.9h.UV index
January, February, November and December, with an average maximum UV index of 2, are months with the lowest UV index. A UV Index estimate of 2, and below, represents a low health risk from unsafe exposure to UV radiation for the ordinary person.Note: The UV index of 2 in January translates into these instructions:
Babies, children, and individuals with sensitive skin should always have protection against extended sun exposure. The Sun's most harmful UV rays are emitted around midday; avoid staying outdoors for long during this time. Sunglasses providing both UVA and UVB protection are non-negotiable on sunlit days. Mind you! Snow reflection can increase the intensity of the Sun's UV radiation nearly twofold.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
How cold is it in January?
What is the average humidity in January?
What is the driest month?
How many days does it rain in January?
How much does it snow in January?
How many hours of daylight does Boulder have in January?
What time are sunrise and sunset in January?
How long on average sun shines in January?
When is the lowest UV index?
How high is the UV index in January?
Average temperature in January
Boulder, CO
- Average high temperature in January: 36.7°F
The warmest month (with the highest average high temperature) is July (80.4°F).
The month with the lowest average high temperature is December (35.2°F).
- Average low temperature in January: 19°F
The month with the highest average low temperature is July (55.2°F).
The coldest month (with the lowest average low temperature) is February (18°F).
Average pressure in January
Boulder, CO
- Average pressure in January: 30.15"Hg
The month with the highest atmospheric pressure is January (30.15"Hg).
The months with the lowest atmospheric pressure are April, May and June (29.92"Hg).
Average wind speed in January
Boulder, CO
- Average wind speed in January: 7.3mph
The windiest month (with the highest average wind speed) is January (7.3mph).
The calmest months (with the lowest average wind speed) are May, July, August and September (5.7mph).
Average humidity in January
Boulder, CO
- Average humidity in January: 68%
The month with the highest relative humidity is February (70%).
The months with the lowest relative humidity are June, August and September (45%).
Average rainfall in January
Boulder, CO
- Average rainfall in January: 0.39"
The wettest month (with the highest rainfall) is May (2.48").
The driest month (with the least rainfall) is January (0.39").
Average rainfall days in January
Boulder, CO
- Average rainfall days in January: 4.3 days
The month with the highest number of rainy days is July (17.8 days).
The month with the least rainy days is November (3.3 days).
Average snowfall in January
Boulder, CO
- Average snowfall in January: 2.87"
The month with the highest snowfall is April (7.76").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days in January
Boulder, CO
- Average snowfall days in January: 6.3 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 January /
Average sunshine in January
Boulder, CO
- Average daylight in January: 9h and 4min
The month with the longest days is June (Average daylight: 15h and 0min).
The month with the shortest days is December (Average daylight: 9h and 24min).
- Average sunshine in January: 6h and 5min
The months with the most sunshine are June and July (Average sunshine: 11h and 42min).
The month with the least sunshine is February (Average sunshine: 6h and 36min).
Average sunshine days in January
Boulder, CO
- Average sunshine days in January: 22.2 days
The month with the most sunshine days is January (22.2 days).
The month with the least sunshine days is July (9.9 days).
Average UV index in January
Boulder, CO
- Average UV index in January: 2
The months with the highest UV index are June, July and August (UV index 5).
The months with the lowest UV index are January, February, November and December (UV index 2).
Average cloud cover in January
Boulder, CO
- Average cloud cover in January: 22
The months with the most cloud cover are April and May (Cloud cover 28).
The month with the least cloud cover is September (Cloud cover 16).
Average visibility in January
Boulder, CO
- 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).
Boulder, Colorado, USA
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