Spring frost

Climatic condition at a temperature below 0 °Celsius or 32 °Fahrenheit. In general, the air temperature is measured at a height of 1.25 metres above the ground; at this height, temperatures are always slightly higher than at ground level. In meteorology, frost at ground level is referred to as ground frost. A basic distinction is made between radiation frost and adjective frost. Radiation frost occurs on dry, clear nights with no wind, when the heat radiated from the ground or plant tissue escapes unhindered into the atmosphere due to the absence of clouds, fog or haze. The coldest (and heaviest) air sinks to the ground and collects on the surface, preferably in low-lying depressions. The adjective (meaning "added") frost is caused by the inflow of already cooled air from other places. This can come from very distant areas such as a long valley.

Protection from frost

A certain degree of protection can be achieved by taking appropriate measures when planting the vineyards. A hillside location from which the cold air flows into lower areas (air drainage) and high forms of cultivation are of great advantage. Low-lying and flat areas are most at risk. Frost control in the vineyard is achieved using wind machines (or even helicopters), which artificially mix the air with the warmer air in the upper layers. Warming smoke ovens, large heaters and similar means are also used. Artificial irrigation can cause direct warming of the vines and the soil because heat is released when the water freezes or a thin layer of ice on plant parts also forms a protective coating.

Late frost & early frost

In the northern hemisphere, frost in spring is generally referred to as late frost (also May frost in the month in question) and in late summer/autumn as early frost. In the course of the annual Vegetationszyklusvegetation...