This rotation allows us to experience day and night. Climatologists usually use full months to represent the seasons. Winter is considered December, January and February; spring is March through May; summer is June through August; and fall or autumn is September through November.

Winter is often defined by meteorologists to be the three calendar months with the lowest average temperatures. This corresponds to the months of December, January and February in the Northern Hemisphere, and June, July and August in the Southern Hemisphere.

winter, coldest season of the year, between autumn and spring; the name comes from an old Germanic word that means “time of water” and refers to the rain and snow of winter in middle and high latitudes.

The solstice usually – but not always – takes place on December 21. The date that the solstice occurs can move forward or back by a day because the solar year (the time it takes for the sun to reappear in the same spot as seen from Earth) doesn't match up exactly to our calendar year.