Cool
Average highs are around 3°C, so pack for cooler days.
January verdict
O'Fallon, Illinois, United States in January
Weather score34Poor
Poor for holiday weather
Average highs are around 3°C, so pack for cooler days. Sunshine averages 5h per day, enough for a balanced month. Rainfall averages 49mm, which is relatively low for holiday planning.
January weather
Monthly averages
Temp
3°C
Rain
49mm
Sun
5h
Weather score
34
Poor
Seasonal climate calendar
TemperatureTemp
RainRain
SunSun
Weather scoreWeather score
Trip feel
Drier
Rainfall averages 49mm, which is relatively low for holiday planning.
Some sun
Sunshine averages 5h per day, enough for a balanced month.
Map
Weather map
Compare O'Fallon, Illinois, United States with nearby places by weather score, rain, sun, temperature, and swim conditions.
Temperature
January3°C average high
January has some of the coolest average daytime highs of the year, so pack for fresher conditions.
Warmest monthsMay to September
This stretch sets the upper range for average daytime heat.
Rain
January49mm average rain
January is one of O'Fallon's driest months, making outdoor days easier to plan than in wetter parts of the year.
Driest monthsJanuary to February and October to December
This is the drier part of the year, when outdoor plans usually need less weather flexibility.
Sun
January5 hours average sun
January is below O'Fallon's yearly sunshine average, so bright-day planning is less reliable than in peak months.
Brightest monthsMay to August
This stretch has the strongest sunshine in the monthly averages.
Weather score
January34 weather score
January is one of the weakest weather-score months, when the overall mix is less favourable than the rest of the year.
Best weather monthsJune to September
These months have the strongest weather score in the monthly averages.
