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 an average high of 37.4°F (3°C) and a low of 23.7°F (-4.6°C), signifies the coldest month of the year.Humidity
In January, the average relative humidity is 75%.Rainfall
In O'Fallon, in January, it is raining for 7.2 days, with typically 1.14" (29mm) of accumulated precipitation. In O'Fallon, during the entire year, the rain falls for 132.3 days and collects up to 21.06" (535mm) of precipitation.Snowfall
Months with snowfall are January through March, November and December. In O'Fallon, during January, snow falls for 5.8 days and regularly aggregates up to 0.98" (25mm) of snow. Throughout the year, there are 19 snowfall days, and 4.13" (105mm) of snow is accumulated.Daylight
The average length of the day in January is 9h and 49min.On the first day of January, sunrise is at 7:21 am and sunset at 4:51 pm. On the last day of the month, sunrise is at 7:09 am and sunset at 5:22 pm CST.
Sunshine
The months with the least sunshine are January and February, with an average of 4.7h of sunshine.UV index
January, February, November and December, with an average maximum UV index of 2, are months with the lowest UV index in O'Fallon. A UV Index of 2, and less, symbolizes a minimal health vulnerability from unsafe exposure to UV radiation for the average person.Note: An average maximum UV index of 2 in January leads to these recommendations:
Sun exposure does not present considerable issues for many, yet infants, fair-skinned people, and children necessitate constant protection. Around midday, solar radiation is most harmful; hence, exposure should be limited. Arm yourself against UV rays' harm with protective apparel and UV-filtering shades. Note well! The intensity of the Sun's UV rays can be nearly doubled by snow reflection.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What are the coldest months?
How cold is January?
What is the average humidity in January?
How much does it rain in January?
How many days does it snow in January?
What is the average length of the day in January?
When are sunrise and sunset in January?
What are the months with the least sunshine?
How long on average sun shines in January?
What are the months with the lowest UV index?
How high is the UV index in January?
Average temperature in January
O'Fallon, MO
- Average high temperature in January: 37.4°F
The warmest month (with the highest average high temperature) is July (87.1°F).
The month with the lowest average high temperature is January (37.4°F).
- Average low temperature in January: 23.7°F
The month with the highest average low temperature is July (68.5°F).
The coldest month (with the lowest average low temperature) is January (23.7°F).
Average pressure in January
O'Fallon, MO
- 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 (29.92"Hg).
Average wind speed in January
O'Fallon, MO
- Average wind speed in January: 9.1mph
The windiest month (with the highest average wind speed) is January (9.1mph).
The calmest month (with the lowest average wind speed) is July (5.5mph).
Average humidity in January
O'Fallon, MO
- Average humidity in January: 75%
The month with the highest relative humidity is May (79%).
The month with the lowest relative humidity is October (70%).
Average rainfall in January
O'Fallon, MO
- Average rainfall in January: 1.14"
The wettest month (with the highest rainfall) is May (2.76").
The driest month (with the least rainfall) is December (0.91").
Average rainfall days in January
O'Fallon, MO
- Average rainfall days in January: 7.2 days
The month with the highest number of rainy days is May (15.7 days).
The month with the least rainy days is February (6.8 days).
Average snowfall in January
O'Fallon, MO
- Average snowfall in January: 0.98"
The month with the highest snowfall is February (1.61").
The months with the least snowfall are April, May, June, July, August, September and October (0").
Average snowfall days in January
O'Fallon, MO
- Average snowfall days in January: 5.8 days
The months with the highest number of snowfall days are January and February (5.8 days).
The months with the least snowfall days are May, June, July, August, September and October (0 days).
Average daylight in January /
Average sunshine in January
O'Fallon, MO
- Average daylight in January: 9h and 5min
The month with the longest days is June (Average daylight: 14h and 48min).
The month with the shortest days is December (Average daylight: 9h and 30min).
- Average sunshine in January: 4h and 4min
The month with the most sunshine is June (Average sunshine: 10h and 30min).
The months with the least sunshine are January and February (Average sunshine: 4h and 42min).
Average sunshine days in January
O'Fallon, MO
- Average sunshine days in January: 20.4 days
The month with the most sunshine days is December (20.6 days).
The month with the least sunshine days is July (12.6 days).
Average UV index in January
O'Fallon, MO
- Average UV index in January: 2
The months with the highest UV index are May, June, July and August (UV index 6).
The months with the lowest UV index are January, February, November and December (UV index 2).
Average cloud cover in January
O'Fallon, MO
- Average cloud cover in January: 50
The month with the most cloud cover is January (Cloud cover 50).
The months with the least cloud cover are June, July, August and September (Cloud cover 28).
Average visibility in January
O'Fallon, MO
- 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).
O'Fallon, Missouri, USA
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