Autumn Weather Update

Autumn is fast approaching as witnessed by shorter days, ripening pumpkins and combines in the field and if Mother Nature acts accordingly, Missouri’s growing season will be coming to an end in the next 4-7 weeks. Depending on where you live in Missouri can make a big difference when to expect your first frost. Missouri’s latitudinal variation, the Ozark Plateau, river bottomlands and hills and valleys are all factors contributing to frost potential. If you have an established climate record of temperatures for your region and an idea of how local topography can affect temperature, you can use that knowledge in determining when, on average, to expect your first fall frost.

The following map displays the median date of the first fall frost (¡Ü32 degrees) in Missouri. These are dates in the fall when there is a 50 percent chance of a light killing frost before and after that date. Typically, the first fall frost occurs over northern and central Missouri by the second and third week of October, respectively. Frosts are more likely to be experienced earlier in the fall over the Ozarks when compared to central Missouri. The reason for this is due to the higher elevation of the Ozark Plateau which causes cooler temperatures in the Ozark region than would be expected. As the Ozark Plateau transitions to the southeastern lowlands, the median first fall frost occurs from as early as the third week of October to the first week of November in the Bootheel tip.

Pat Guinan