Chicago Weather: Freeze Warning Starts At Midnight

CHICAGO (CBS) -- Winds relax overnight as the center of cold air moves into our area.

A hard freeze is likely overnight in outlying areas where lows will drop into the 20s.

This air mass is quite cold for this time of year. It is interesting that all counties (even lakeside) are included in the warning. This is because the air mass originated from the Arctic.

Sensitive plants should be covered or pulled inside if possible.

Saturday will be sunny with highs in the upper 50s. Rain showers arrive by mid-morning on Sunday.

A few thunderstorms are possible Sunday afternoon.

Our normal high is 68 degrees.