Meteorologists Celebrate Spring on March 1

Got story updates? Submit your updates here. ›

As the calendar flips to March, meteorologists in the Northern Hemisphere are welcoming the start of spring, even though the astronomical spring equinox comes later in the month. Meteorologists follow a different seasonal calendar than the astronomical one, marking the change of seasons based on temperature patterns rather than the position of the Earth relative to the sun.

Why it matters

The difference between the meteorological and astronomical calendars can cause some confusion, as the public may expect spring to officially begin on the equinox rather than on March 1. However, the meteorological approach aligns better with how weather patterns actually shift over the course of the year.

The details

Meteorologists define the seasons based on the annual temperature cycle, with spring running from March 1 to May 31, summer from June 1 to August 31, fall from September 1 to November 30, and winter from December 1 to February 28 (or 29 in a leap year). This makes it easier to track seasonal trends and averages. In contrast, the astronomical seasons are determined by the Earth's position relative to the sun, with the spring equinox typically falling around March 20.

• Meteorological spring begins on March 1 each year.
• The astronomical spring equinox typically occurs around March 20.

What they’re saying