Watering is Necessary for Plants in Frost and Hot Air| Extreme Weather is explained.
Frost and hot air current damages plant. Watering plant can prevent damage in winter and summer. In winter water on the surface of plant convert into solid state,ie,snow. The conversion of the water from liquid state to solid state releases energy in the form of heat. This heat keeps plant warm.
In summer plants releases water due to transpiration. So, watering in summer keep plants cool.