What s the difference between meteorological winter and astronomical winter?
Meteorologists and climatologists define winter as December 1 through the last day of February. However, astronomical winter often described as official winter begins on the winter solstice (on or around December 21) and lasts until the spring equinox (on or around March 21). For each of the four seasons, the astronomical season lags behind the meteorological season by about three weeks. This USA TODAY FAQ page has more about the seasons, while this page has a link to a graphic that explains how the Earth’s tilt creates the four seasons.
