Winter phenomena

astronomical phenomenon that occurs in December in Northern Hemisphere and in June in Southern Hemisphere

event in which the varieties of precipitation are formed that only occur at low temperatures

rise in temperature after freezing weather

thumb|Many species of henbane require vernalization before flowering.

thumb|Migration of cranes Overwintering is the process by which some organisms pass through or wait out the winter season, or pass through that period of the year when "winter" conditions (cold or sub-zero temperatures, ice, snow, limited food supplies) make normal activity or even survival difficult or near impossible. In some cases "winter" is characterized not necessarily by cold but by dry conditions; passing through such periods could likewise be called overwintering.

annual state for some plants and animals