Temperatures will dip near the freezing mark early Saturday on the southern edge of a cold front that includes the Arkansas River Valley, the National Weather Service reports.
Early spring crops could be threatened by frost, and plants outdoors may be at risk with temperatures dropping near 33 degrees in Fort Smith.
Areas of frost are expected after 3 a.m. Saturday.
The warning is for an area of western and northwest Arkansas, eastern and northeast Oklahoma and much of Kansas and Missouri.
The freeze warning is in effect from 1 a.m. to 8 a.m. Saturday in Fort Smith.