Weather is an environment element in the game. Currently there are four type of weather - Clear, Overcast, Rain, and Snow.
Cloudy weather is characterized by reduced ambient lighting (to near black at night) and gray skies.
Drops of water are falling down from the skies, making a splash effect when hitting the ground. The sky appears overcast. A Blockhead doesn't like to be out from shelter when it is raining and if he/she does, his/her environment bar will be decreased. It may snow above locations where it is raining.
The least common weather, mostly appearing near the poles. Increasingly likely at higher altitudes. Snowflakes are falling from the sky and cover the surface with snow, deepening as more falls without any "melting" due to warmer air.
Water blocks exposed to the cold air associated with snow may turn into ice, sometimes to a considerable depth. A Blockhead should wear warm articles of clothing in order to prevent freezing (and a possible loss of health. The North Pole Hat of Warmth is most effective.