| Term: | Ground frost |
| Definition: | In British usage, a freezing condition injurious to vegetation, which is considered to have occurred when a minimum thermometer exposed to the sky at a point just above a grass surface records a temperature (grass temperature) of -0.9C (30.4F) or below. Since 1961 in Britain the statistics refer to the "number of days with grass minimum temperature below 0C" rather than to ground frost. A fuller discussion is given in McIntosh (1963). |