National Weather Service Weather Forecast Office

 The weekend will end on a cool note before a significant warm-up for Tuesday and Wednesday.  Frost is looking likely in outlying areas tonight and a Frost Advisory has been issued.   

Click here for a regional map of the average last freeze date.

In order to gauge the risk of experiencing freezing temperatures through the spring season, consider the tables below.  These tables display the probabilities of exceedance for the date of the last spring freeze (32 degrees and colder), as well as the date of the last spring season hard freeze (28 degrees and colder) at both Chicago and Rockford. To interpret these tables consider, for example, the 10th percentile for Chicago in the table below. The date listed is May 7th for the date of the last freeze.  This means that of all the years in the history for Chicago dating back to the late 1800s 10% of the years experienced the final spring freeze on a date later than May 7th.   So, statistically speaking there is a 10% chance that freezing temperatures will still be observed at least once after April 12th.  Notice the dates at Rockford are later.  

Observed Last Freeze Thus Far: