With spring planting about to begin, it is important to remember that freezing temperatures typically occur well into April over central and southeast Illinois. Much of the area will see the last freeze around mid April, with hard freezes (lows of 28°F or colder) still possible through the first several days of the month. The images below, from data by the National Climatic Data Center and the Illinois State Climatologist Office, show the median date of the last freeze (left image) and hard freeze (right image) over our area. Click the images to enlarge.
The Midwestern Regional Climate Center in Champaign updates the following maps daily to keep track of when the last freeze and hard freeze have occurred. Click the images to enlarge. Data for other states is available at this link.