National Weather Service United States Department of Commerce

A nice night is on tap across the region with clear skies and seasonably cool temperatures. Clouds will be on the increase Monday but we will still see some sun. High temperatures will be pretty close to average for this time of the year. As we head into Monday night the clouds will continue to thicken and there is a chance of showers across southeast Missouri and southern Illinois.
Temperatures will be mild this week, with highs topping out in the 60s and lows in the 40s. Some locations will see lows drop into the mid to upper 30s midweek. There's a low chance of rain Monday night over southeastern Missouri and southwestern Illinois, and then again area-wide on Friday.
Frost may occur for portions of central and eastern Missouri, as well as west-central Illinois early Wednesday morning and then again early Thursday morning. Overnight lows for these days have been trending cooler recently, and if cooler lows occur than what is currently forecast, the threat of frost may increase area-wide.