frost point

noun

1. the temperature of the air at which hoarfrost begins to form.

Example Sentences

As for the process of "lofting" the grains off the ground, the paper suggests that the driver could be a slight warming from the distant Sun, raising the temperature above the frost point of nitrogen: -230C.

From BBC

It forms when the temperature drops to the “frost point” — which is simply the dew point, if it happens to be below freezing.

From Washington Post

The swaying of the limbs, when agitated by the breeze, gives them tone and strength, and may assist in the circulation of the sap within their cells; and the constant agitation of the atmosphere, commingling the warmer with the colder portions, will often modify the temperature to such an extent as to give an immunity from the frost in the open prairie, at the same moment that the more tranquil air, within a limited clearing of forest lands, has been cooled down, by radiation, to the frost point.

From Project Gutenberg

Originally, the temperature of the southern polar cap was reported as -180�F., or roughly the frost point of carbon dioxide under Martian atmospheric pressure.

From Time Magazine Archive

Its infra-red radiometer measured the temperature of the area at � 253�F., or roughly the frost point of carbon dioxide on Mars.

From Time Magazine Archive