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, with its average high-temperature of 22.5°F (-5.3°C) and an average low-temperature of 9.9°F (-12.3°C), holds the record as the coldest month.Humidity
January is the most humid month, with an average relative humidity of 89%.Rainfall
The month with the least rainfall is January, when the rain falls for 4 days and typically collects 0.98" (25mm) of precipitation.Snowfall
January through May, October through December are months with snowfall. In Castalia, during January, snow falls for 13.3 days and regularly aggregates up to 5" (127mm) of snow. Throughout the year, there are 52.3 snowfall days, and 21.26" (540mm) of snow is accumulated.Daylight
The average length of the day in January is 9h and 26min.On the first day of the month, sunrise is at 7:38 am and sunset at 4:42 pm. On the last day of January, sunrise is at 7:23 am and sunset at 5:17 pm CST.
Sunshine
The month with the least sunshine is January, with an average of 3.5h of sunshine.UV index
The months with the lowest UV index are January, November and December, with an average maximum UV index of 1. A UV Index estimate of 2, and below, represents a minimal health vulnerability from exposure to the Sun's UV radiation for average individuals.Note: An average UV index of 1 in January transforms into this advice:
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 intensity of the Sun's UV radiation during midday suggests reducing time spent outdoors. Sunglasses that guard against UVA and UVB rays are pivotal in minimizing sun-induced ocular damage. Mark this! Snow reflection can nearly double the UV radiation intensity from the Sun.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What month is the coldest?
How cold is January?
What is the most humid month?
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 Castalia have in January?
When is the sunrise / sunset in January in Castalia?
What is the month with the least sunshine?
How many hours of sunshine does Castalia have in January?
What are the months with the lowest UV index?
What is the UV index intensity in January?
Average temperature in January
Castalia, IA
- Average high temperature in January: 22.5°F
The warmest month (with the highest average high temperature) is July (79°F).
The month with the lowest average high temperature is January (22.5°F).
- Average low temperature in January: 9.9°F
The month with the highest average low temperature is July (62.2°F).
The coldest month (with the lowest average low temperature) is January (9.9°F).
Average pressure in January
Castalia, IA
- Average pressure in January: 30.13"Hg
The month with the highest atmospheric pressure is January (30.13"Hg).
The month with the lowest atmospheric pressure is June (29.89"Hg).
Average wind speed in January
Castalia, IA
- Average wind speed in January: 10.2mph
The windiest month (with the highest average wind speed) is April (10.5mph).
The calmest months (with the lowest average wind speed) are July and August (7mph).
Average humidity in January
Castalia, IA
- Average humidity in January: 89%
The month with the highest relative humidity is January (89%).
The month with the lowest relative humidity is October (75%).
Average rainfall in January
Castalia, IA
- Average rainfall in January: 0.98"
The wettest month (with the highest rainfall) is June (4.33").
The driest month (with the least rainfall) is January (0.98").
Average rainfall days in January
Castalia, IA
- Average rainfall days in January: 4 days
The month with the highest number of rainy days is June (17.7 days).
The month with the least rainy days is February (3.8 days).
Average snowfall in January
Castalia, IA
- Average snowfall in January: 5"
The month with the highest snowfall is February (5.16").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days in January
Castalia, IA
- Average snowfall days in January: 13.3 days
The month with the highest number of snowfall days is January (13.3 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in January /
Average sunshine in January
Castalia, 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 6min).
- Average sunshine in January: 3h and 3min
The month with the most sunshine is August (Average sunshine: 9h and 48min).
The month with the least sunshine is January (Average sunshine: 3h and 30min).
Average sunshine days in January
Castalia, IA
- Average sunshine days in January: 15.3 days
The month with the most sunshine days is September (17 days).
The month with the least sunshine days is June (10.5 days).
Average UV index in January
Castalia, IA
- Average UV index in January: 1
The month with the highest UV index is July (UV index 6).
The months with the lowest UV index are January, November and December (UV index 1).
Average cloud cover in January
Castalia, IA
- Average cloud cover in January: 64
The month with the most cloud cover is January (Cloud cover 64).
The month with the least cloud cover is August (Cloud cover 32).
Average visibility in January
Castalia, IA
- Average visibility in January: 5mi
The months with the highest visibility are March, April, May, June, August, September, October, November and December (6mi).
The months with the lowest visibility are January, February and July (5mi).
Castalia, Iowa, USA
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