Frost potential early next week
The first frost of the season could be just a few days away.
Chilly, Canadian air will settle into the area this weekend which will carry over into the new week. High temperatures are expected to be below-normal and generally in the 50s through the weekend and for most of next week.
Night lows will drop into the upper 30s to lower 40s this weekend. However, there are signs that temperatures may drop into the mid-30s Sunday night and Monday night which could lead to areas of frost. It is dependent on cloud cover and winds. Clouds keep temperatures warmer at night and act like a blanket trapping the warmer air at the surface as opposed to clear skies which allow the leftover solar radiation to escape back to space hence resulting in cooler temperatures. Winds mix up the air which aids in frost prevention so calm conditions are ideal for frost development.
On average, the first frost in southeast Minnesota and northern Iowa occurs during the first week or two of October.