Frost day

Alternative definitions (1), class: vernacular (0)
Term: Frost day
Definition: An observational day on which frost occurs; one of a family of climatic indicators (e.g., thunderstorm day, rain day). The definition is somewhat arbitrary, depending upon the accepted criteria for a frost observation. Thus, it may be 1) a day on which the minimum air temperature in the thermometer shelter falls below 0C (32F); 2) a day on which a deposit of white frost is observed on the ground; 3) in British usage, a day on which the minimum temperature at the level of the ground or on the tops of low, close-growing vegetation falls to -0.9C (30.4F) or below (also called a "day with ground frost"); and perhaps others. The present trend is to drop such terms in favor of something less ambiguous, such as "day with minimum temperature below 0C (32F)."
Created 2022.03.08
Last Modified 2023.03.27
Contributed by GCW Glossary