CLEVELAND — Some folks in the snowbelt might argue that winter began as soon as the snow started falling, but there are technically two “starts” to winter.
There is Meteorological Winter and Astronomical Winter. They are just different ways of dividing up our seasons. Meteorological Winter began on December 1st. Astronomical Winter begins Saturday December 21st at 4:19 am this year.
Meteorological winter is based on the annual temperature cycle and the calendar. It is defined as the three typically coldest months of the year. It always starts on December 1 and ends on February 28/29 (in leap years). The idea of Meteorological Winter is used by meteorologists and climatologists for consistency in tracking and comparing weather data. Grouping seasons by calendar months simplifies statistical analysis.
Astronomical Winter is determined by Earth's position relative to the Sun, specifically starting with the winter solstice. In the Northern Hemisphere, it typically begins around December 21 or 22 (the winter solstice) and ends around March 20 or 21 (the spring equinox). This definition is tied to the Earth's tilt and orbit, marking the shortest day of the year and the gradual return of longer daylight hours.
Meteorological Winter is a practical, temperature-based framework, while Astronomical Winter reflects Earth's relationship to the Sun and changes in daylight. Both systems serve different but complementary purposes.
