To overwinter is to pass through or wait out the winter season, or to pass through that period of the year when “winter” conditions (cold or sub-zero temperatures, ice

Ice

Ice is water frozen into the solid state. Usually ice is the phase known as ice Ih, which is the most abundant of the varying solid phases on the Earth's surface. It can appear transparent or opaque bluish-white color, depending on the presence of impurities or air inclusions...

, snow

Snow

Snow is a form of precipitation within the Earth's atmosphere in the form of crystalline water ice, consisting of a multitude of snowflakes that fall from clouds. Since snow is composed of small ice particles, it is a granular material. It has an open and therefore soft structure, unless packed by...

, 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. Alternately, overwintering can refer to spending winter in a more favourable (usually warmer) locale.

Hibernation

Hibernation

Hibernation is a state of inactivity and metabolic depression in animals, characterized by lower body temperature, slower breathing, and lower metabolic rate. Hibernating animals conserve food, especially during winter when food supplies are limited, tapping energy reserves, body fat, at a slow rate...

 and Migration are the two major ways in which overwintering is accomplished.

Common uses

The term overwinter is used in several contexts. Some of these follow:

• In entomology
  Entomology
  Entomology is the scientific study of insects, a branch of arthropodology...
  
  , overwintering is often the term used to describe how an insect
  Insect
  Insects are a class of living creatures within the arthropods that have a chitinous exoskeleton, a three-part body , three pairs of jointed legs, compound eyes, and two antennae...
  
   passes the winter season. Many insects overwinter as adults, pupae, or eggs. This can be done inside buildings, under tree bark, or beneath fallen leaves or other plant matter on the ground, among other places. All such overwintering sites shield the insect from adverse conditions associated with winter. Activity almost completely ceases until conditions become more favourable. Other insects, such as the monarch butterfly
  Monarch butterfly
  The Monarch butterfly is a milkweed butterfly , in the family Nymphalidae. It is perhaps the best known of all North American butterflies. Since the 19th century, it has been found in New Zealand, and in Australia since 1871 where it is called the Wanderer...
  
  , migrate and overwinter in warmer areas.
• Many bird
  Bird
  Birds are feathered, winged, bipedal, endothermic , egg-laying, vertebrate animals. Around 10,000 living species and 188 families makes them the most speciose class of tetrapod vertebrates. They inhabit ecosystems across the globe, from the Arctic to the Antarctic. Extant birds range in size from...
  
  s migrate and then overwinter in regions where temperatures are warmer or food is more readily available.
• Plant
  Plant
  Plants are living organisms belonging to the kingdom Plantae. Precise definitions of the kingdom vary, but as the term is used here, plants include familiar organisms such as trees, flowers, herbs, bushes, grasses, vines, ferns, mosses, and green algae. The group is also called green plants or...
  
  s are sometimes said to overwinter. At such times, growth of vegetative tissues and reproductive structures becomes minimal or ceases completely. For plants, overwintering often involves restricted water supplies and reduced light exposure. In the spring following overwintering many plants will enter their flowering stage.
• People are also described from time to time as overwintering. This was especially true in the past during the exploration of the planet when people had to pass the winter in places not ideally suited for winter survival, and even today in the polar region
  Polar region
  Earth's polar regions are the areas of the globe surrounding the poles also known as frigid zones. The North Pole and South Pole being the centers, these regions are dominated by the polar ice caps, resting respectively on the Arctic Ocean and the continent of Antarctica...
  
  s. Today people may be said to overwinter when they temporarily move to warmer areas during the months of prevailing cold weather in northern latitudes, such as people from various parts of North America
  North America
  North America is a continent wholly within the Northern Hemisphere and almost wholly within the Western Hemisphere. It is also considered a northern subcontinent of the Americas...
  
   staying in Florida
  Florida
  Florida is a state in the southeastern United States, located on the nation's Atlantic and Gulf coasts. It is bordered to the west by the Gulf of Mexico, to the north by Alabama and Georgia and to the east by the Atlantic Ocean. With a population of 18,801,310 as measured by the 2010 census, it...
  
  , Arizona, or New Mexico (among other places) for parts of November to March.
• In plant pathology, overwintering is where a plant pathogen survives the winter, during which its normal crop
  Crop
  Crop may refer to:* Crop, a plant grown and harvested for agricultural use* Crop , part of the alimentary tract of some animals* Crop , a modified whip used in horseback riding or disciplining humans...
  
   host
  Host (biology)
  In biology, a host is an organism that harbors a parasite, or a mutual or commensal symbiont, typically providing nourishment and shelter. In botany, a host plant is one that supplies food resources and substrate for certain insects or other fauna...
  
  species is not growing, by transferring to an alternative host, living freely in the soil or surviving on plant refuse such as discarded potatoes.