When does winter actually begin?

It is dark, (possibly) wet, and chilly outside. Three indicators that winter is here… but is it actually?

There are two definitions when it comes to winter. You could look at it meteorologically or astronomically.

The simple version lays with the meteorological definition. Here, the seasons are split using the standard calendar with each season lasting three full months. In this system, winter will begin next week, on December 1st and last until March 1st when spring arrives.

Now for the astronomers out there. Using the astronomical definition we look towards the winter solstice. Since this changes slightly each year there is a new start date for winter annually.

This year, the astronomical winter season will begin on or on either side of December 21st, lasting until March 20th.