Days of Ground Frost – Annual Average
The days of ground frost are recorded as the number of days where the ground minimum temperature is less than 0˚C. Ground frost is closely related to both altitude and sea temperature. Ground frost mostly (but not exclusively) occurs during winter, and during these months the sea temperature regulates the air temperature due to its latent heat properties. The sea takes longer to heat up and cool down than the land, so the sea is still relatively warm from the summer temperatures and this influences land temperature close to the coast. Inland the number of ground frost days is considerably greater, and increases with altitude to peak in the uplands.