We get a lot of questions from readers here at the Farmers’ Almanac, and we do our best to answer each one. This was a recent question about meteorological seasons versus astronomical seasons via Facebook:
Q: What’s the difference between meteorological and astronomical winter?
A: Meteorologists define “winter” as the three coldest months of the year: December, January, and February. So to them, winter begins on December 1st and ends at the end of February (February 29th in 2020). And the first day of meteorological spring is considered March 1st, with the three months of spring being March, April, and May.
Astronomers, on the other hand, define “winter” in the Northern Hemisphere by when the noontime Sun reaches its farthest point south in the sky; or when the Sun’s rays shine down from a point directly overhead as seen from the tropic of Capricorn (latitude 23.5 degrees south), known as the winter solstice. That happens on December 21 (or 22, depending on the year). And it continues as such until the direct solar rays shine down on the equator at the vernal or Spring Equinox on March 19th (in 2020 — the date and time of spring changes from year to year).
In short, the seasons you are familiar with, by the calendar, are “astronomical,” and the seasons that your meteorologist chats about on the evening news are “meteorological.” So to them, spring begins March 1st!
What do you think: should December 1st be the official start of winter and March 1st be the official start of spring? Share your thoughts in the comments below.