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
January, recording an average high temperature of 24.1°F (-4.4°C) and a low temperature of 10.8°F (-11.8°C), is Rock Valley's coldest month.Humidity
January is the most humid month in Rock Valley, with an average relative humidity of 87%.Rainfall
The month with the least rainfall in Rock Valley, Iowa, is January, when the rain falls for 4.2 days and typically collects 0.75" (19mm) of precipitation.Snowfall
Months with snowfall in Rock Valley are January through May, October through December. In Rock Valley, in January, snow falls for 11.8 days, with typically accumulated 3.23" (82mm) of snow. Throughout the year, in Rock Valley, there are 49.2 snowfall days, and 19.41" (493mm) of snow is accumulated.Daylight
In Rock Valley, the average length of the day in January is 9h and 25min.On the first day of January in Rock Valley, sunrise is at 7:57 am and sunset at 5:00 pm. On the last day of the month, sunrise is at 7:41 am and sunset at 5:35 pm CST.
Sunshine
The month with the least sunshine in Rock Valley is January, with an average of 4.1h of sunshine.UV index
January, February, 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 exposure to the Sun's UV rays for the average person.Note: A daily maximum UV index of 2 in January translates into the following instructions:
People with sensitive skin, children, and babies should always be protected from prolonged sun exposure. To prevent harmful UV exposure, minimize direct contact with the Sun around midday. To mitigate harm from sun exposure, pick sunglasses offering UVA and UVB defense. Be aware! The reflective nature of snow can magnify the Sun's UV radiation almost twofold.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What time of the year is the coldest in Rock Valley?
How cold is it in Rock Valley in January?
What is the most humid month in Rock Valley?
What is the average humidity in January in Rock Valley?
What is the driest month in Rock Valley?
How many days does it rain in January in Rock Valley?
How many days does it snow in January in Rock Valley?
How many hours of daylight does Rock Valley have in January?
When is the sunrise / sunset in January in Rock Valley?
What is the month with the least sunshine in Rock Valley?
How many hours of sunshine does Rock Valley have in January?
What is the month with the lowest UV index in Rock Valley?
How high is the UV index in January in Rock Valley?
Average temperature in January
Rock Valley, IA
- Average high temperature in January: 24.1°F
The warmest month (with the highest average high temperature) is July (81.9°F).
The month with the lowest average high temperature is January (24.1°F).
- Average low temperature in January: 10.8°F
The month with the highest average low temperature is July (63.5°F).
The coldest month (with the lowest average low temperature) is January (10.8°F).
Average pressure in January
Rock Valley, IA
- Average pressure in January: 30.16"Hg
The month with the highest atmospheric pressure is January (30.16"Hg).
The month with the lowest atmospheric pressure is June (29.86"Hg).
Average wind speed in January
Rock Valley, IA
- Average wind speed in January: 10.4mph
The windiest month (with the highest average wind speed) is April (11.2mph).
The calmest month (with the lowest average wind speed) is July (7.8mph).
Average humidity in January
Rock Valley, IA
- Average humidity in January: 87%
The month with the highest relative humidity is January (87%).
The month with the lowest relative humidity is October (67%).
Average rainfall in January
Rock Valley, IA
- Average rainfall in January: 0.75"
The wettest month (with the highest rainfall) is June (3.78").
The driest month (with the least rainfall) is January (0.75").
Average rainfall days in January
Rock Valley, IA
- Average rainfall days in January: 4.2 days
The month with the highest number of rainy days is June (18.8 days).
The month with the least rainy days is February (3.3 days).
Average snowfall in January
Rock Valley, IA
- Average snowfall in January: 3.23"
The month with the highest snowfall is February (4.49").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days in January
Rock Valley, IA
- Average snowfall days in January: 11.8 days
The month with the highest number of snowfall days is January (11.8 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in January /
Average sunshine in January
Rock Valley, IA
- Average daylight in January: 9h and 2min
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 0min).
- Average sunshine in January: 4h and 1min
The month with the most sunshine is July (Average sunshine: 10h and 36min).
The month with the least sunshine is January (Average sunshine: 4h and 6min).
Average sunshine days in January
Rock Valley, IA
- Average sunshine days in January: 17.2 days
The month with the most sunshine days is November (19.7 days).
The month with the least sunshine days is June (8.3 days).
Average UV index in January
Rock Valley, IA
- 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
Rock Valley, IA
- Average cloud cover in January: 55
The month with the most cloud cover is January (Cloud cover 55).
The month with the least cloud cover is July (Cloud cover 27).
Average visibility in January
Rock Valley, IA
- Average visibility in January: 5mi
The months with the highest visibility are February, March, April, May, June, July, August, September, October, November and December (6mi).
The month with the lowest visibility is January (5mi).
Rock Valley, Iowa, USA
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