How Cold Does It Need to Be for Snow?

Snow is formed in clouds when water vapor freezes directly into ice crystals. This requires cold air (at or below 0 °C/32 °F) and enough moisture. In fact, snow crystal growth is most efficient in a “dendritic growth zone” at roughly –12 °C to –18 °C (10 °F to 0 °F), where complex six-sided flakes flourish. In extremely cold clouds (below […]