January weather forecastCastle Rock, CO
January
Weather in January
The month of January in Castle Rock, Colorado, is the start of winter with temperatures reaching a high of 40.1°F (4.5°C) and a low of 20.8°F (-6.2°C). This month is well-known for its persisting chilly vibe but less extreme than the following month. January is characterized by snowy landscapes, as significant snowfall decorates the city. Nicely coated with the beginnings of the winter snow, January also seems to cast a calm over the city. The amount of daylight is noticeably short due to the onset of winter.Temperature
Castle Rock, Colorado, registers an average high-temperature of a still wintry 40.1°F (4.5°C) at the commencement of January, closely related to the preceding month. Throughout January, the nighttime temperature in Castle Rock averages to a freezing cold 20.8°F (-6.2°C).Humidity
The average relative humidity in January is 65%.Rainfall
The months with the least rainfall are January and December Rain falls for 5.1 days and accumulates 0.55" (14mm) of rain.Snowfall
Months with snowfall in Castle Rock are January through June, October through December. In Castle Rock, in January, snow falls for 7.6 days, with typically accumulated 4.02" (102mm) of snow. Throughout the year, there are 51 snowfall days, and 40.43" (1027mm) of snow is accumulated.Daylight
In January, the average length of the day is 9h and 46min.On the first day of January in Castle Rock, sunrise is at 7:19 am and sunset at 4:46 pm. On the last day of the month, sunrise is at 7:07 am and sunset at 5:18 pm MST.
Sunshine
In January, the average sunshine is 7h.UV index
The months with the lowest UV index are January, February, October through December, with an average maximum UV index of 2. A UV Index estimate of 2, and below, represents a low threat to health from exposure to the Sun's UV rays for the average person.Note: The maximum UV index of 2 during January leads to these instructions:
Prolonged sun exposure should always be prevented in babies, children, and those with sensitive skin. The most potent solar radiation is around mid-day, so one should minimize exposure to direct sunlight during this period. Boost your sun resistance with garments that are densely woven yet spacious. Note this! The Sun's UV radiation can nearly be doubled by the reflection off snow.
Published by: Weather Atlas | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in January
Castle Rock, CO
- Average high temperature in January: 40.1°F
The warmest month (with the highest average high temperature) is July (83.3°F).
The month with the lowest average high temperature is December (39.6°F).
- Average low temperature in January: 20.8°F
The month with the highest average low temperature is July (57.2°F).
The coldest month (with the lowest average low temperature) is December (20.1°F).
Average pressure in January
Castle Rock, CO
- Average pressure in January: 30.13"Hg
The month with the highest atmospheric pressure is January (30.13"Hg).
The months with the lowest atmospheric pressure are April and June (29.91"Hg).
Average wind speed in January
Castle Rock, CO
- Average wind speed in January: 7mph
The windiest month (with the highest average wind speed) is April (7.9mph).
The calmest months (with the lowest average wind speed) are July, August and September (6.5mph).
Average humidity in January
Castle Rock, CO
- Average humidity in January: 65%
The month with the highest relative humidity is February (66%).
The months with the lowest relative humidity are June and September (45%).
Average rainfall in January
Castle Rock, CO
- Average rainfall in January: 0.55"
The wettest month (with the highest rainfall) is May (2.24").
The driest months (with the least rainfall) are January and December (0.55").
Average rainfall days in January
Castle Rock, CO
- Average rainfall days in January: 5.1 days
The month with the highest number of rainy days is July (15.1 days).
The month with the least rainy days is November (3 days).
Average snowfall in January
Castle Rock, CO
- Average snowfall in January: 4.02"
The month with the highest snowfall is April (7.13").
The months with the least snowfall are July, August and September (0").
Average snowfall days in January
Castle Rock, CO
- Average snowfall days in January: 7.6 days
The month with the highest number of snowfall days is February (9.8 days).
The months with the least snowfall days are July and August (0 days).
Average daylight in January /
Average sunshine in January
Castle Rock, CO
- Average daylight in January: 9h and 48min
The month with the longest days is June (Average daylight: 14h and 54min).
The month with the shortest days is December (Average daylight: 9h and 24min).
- Average sunshine in January: 7h and 0min
The months with the most sunshine are June, July and August (Average sunshine: 11h and 48min).
The month with the least sunshine is February (Average sunshine: 6h and 48min).
Average sunshine days in January
Castle Rock, CO
- Average sunshine days in January: 21.5 days
The month with the most sunshine days is November (22.8 days).
The month with the least sunshine days is July (10.6 days).
Average UV index in January
Castle Rock, CO
- Average UV index in January: 2
The months with the highest UV index are June and July (UV index 6).
The months with the lowest UV index are January, February, October, November and December (UV index 2).
Average cloud cover in January
Castle Rock, CO
- Average cloud cover in January: 21
The month with the most cloud cover is April (Cloud cover 27).
The month with the least cloud cover is September (Cloud cover 15).
Average visibility in January
Castle Rock, 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).
