Historical weather data, all-time temperature records, and monthly climate averages for Mattoon, IL. Explore typical weather conditions by week for trip planning, and see how today compares to the historical record.
April 5th in Mattoon typically brings mild spring conditions, with average highs around 60° and lows near 39°. History shows the date can swing wildly though — from a balmy 85° back in 1929 to a bitter 22° low in 1920. There's roughly a 1-in-3 chance of rain today, but snow is essentially off the table.
Mattoon's weather has real teeth at the extremes — a scorching 110° in July 1936 and a bone-cracking -27° in January 1994 represent a 137-degree swing in recorded history. A single day in June 1957 dumped 6.5 inches of rain, and a January 1982 snowstorm buried the city under a foot of snow.
Summer is the main event in Mattoon, with the week of July 9–15 averaging highs of 88° — peak time for outdoor plans. January is the dead of winter, with highs barely scraping 37°. If you're watching for rain, late April into early May is the wettest stretch of the year, averaging over an inch of precipitation in a single week.