Chicago Weather: Big Temperature Drop; Overnight Freeze Warning Issued

(CBS) -- Temperatures plunged into the 40s on Friday afternoon as a cold front swept into Chicago.

Tonight, temps will continue to fall into the 30s and wind chills on Saturday morning will feel like the 20s. Chicago woke up to temperatures in the high 60s.  By 3 p.m., it was 44 degrees.

There is a freeze warning overnight for the suburbs, including Belvidere, Crystal Lake, Algonquin, Lake in the Hills, McHenry, Woodstock, Cary, DeKalb, Sycamore, Aurora, Elgin, Oswego, Boulder Hill, Yorkville, and Plano. Temps could fall into the 20s in outlying areas in the purple shaded areas below.

No severe weather is expected, but we will most definitely see showers and storms off and on today. Accordign to reports from DuPage and Grundy County, an inch of rain fell by 9 a.m.--prompting a flood advisory for the area. By mid morning, temperatures were already noticably cooler than they were around daybreak.

The weekend will then be dry, but will be cold.  The start of the Chicago Marathon will be chilly, but that's actually good for the runners.

Highs this weekend will be in the 50s.

The plunge from 70 to the 40s in Chicago is nothing compared with what just happened in Denver.

Thursday evening, the temperature in Denver dropped to a record low of 13 degrees. The previous day, the city hit a high of 83. That ties the second-largest  temperature change in Denver since 1872 when records began.