Illinois will be seeing the first signs of the coming winter.
The National Weather Service says parts of northern and central Illinois will see their first frost by this morning.
High pressure over western Wisconsin through eastern Iowa will drift over Illinois. That, combined with light winds and dry air, will result in temperatures as low as 33 degrees.
The Weather Service has issued a frost advisory from 1 a.m. to 7 a.m.
It warns that sensitive outdoor plants may be killed if left uncovered.