wintertime

Wintertime refers to the period traditionally associated with winter in temperate and polar regions. In common usage it spans December through February in the Northern Hemisphere and June through August in the Southern Hemisphere, though exact boundaries vary. Meteorological winter defines winter as those three calendar months, while astronomical winter begins with the winter solstice and ends with the vernal equinox, dates that shift slightly each year.

Weather and daylight are defining features. Wintertime is characterized by lower average temperatures, frost, and often snow and ice. Daylight hours are shorter, especially at higher latitudes, and some regions experience extended periods of darkness or the polar night. Weather patterns include cold fronts and occasional warm spells; precipitation may fall as snow or rain depending on local conditions.

Impacts and activities commonly associated with wintertime include effects on transportation, energy demand, and public health, with risks such as hypothermia and icy road conditions. Many cultures observe holidays and customs during the season, and people participate in seasonal activities and sports such as skiing, skating, and sledding. Clothing tends to be layered and insulated to protect against cold exposure.

Ecology and geographic variation are notable. In temperate zones, many plants go dormant and deciduous trees shed leaves, while some animals migrate or enter hibernation. Equatorial and tropical regions experience little or no true cold-season winter, instead having distinct wet and dry seasons. In the contemporary era, climate change has altered winter severity and precipitation patterns in various regions, affecting ecosystems and human activities differently around the world.