Favorable for Frost: Why Tonight’s Conditions Are Right For the Formation of Frost

As the days become cooler and we head deeper into the fall season, frosty mornings will become an increasingly common occurrence. Tonight will mark the second widespread frost of the season.

Frost forms when the air temperature cools past the dew-point temperature, which, after this occurs, is renamed the frost point. As temperatures cool and approach the dew-point, the water vapor in the air turns into liquid. When the air cools even further, the liquid freezes, causing a delicate sheet of ice to form in the shallowest layer of the Earth, known as frost.

Conditions that are optimal for frost formation are cool temperatures near the freezing point, minimal winds, and clear skies. This makes tonight extremely favorable for the formation of frost, as all of these conditions are expected to be fulfilled.

This second night of frost will mark the end of the growing season in several locations of Mid-Missouri overnight. It is advised to bring potted plants indoors and cover those that cannot be brought in.