Meteorological spring vs. astronomical spring: What’s the difference?

CHICOPEE, Mass. (WWLP) – The first day of March marks the first day of meteorological spring, while astronomical spring doesn’t start until March 20.

Meteorological seasons take into account the three-month periods. Spring is then March 1 through the end of May. The reason for that?

It makes keeping weather and climate records an easier experience since the start and end date of the seasons is the same no matter the year. Now astronomical seasons.

The Earth takes 365.24 days to travel around the sun, which is why every 4 years we created Leap Years. Because of that, the exact start date and time of solstices and equinoxes vary from year to year. That, and the elliptical shape of Earth’s orbit around the sun, change the astronomical seasons to vary from 89 to 93 days. And that changing start date and time to the different seasons makes it much harder to consistently compare weather and climate statistics from year to year.

That means astronomical spring is officially 21 days away, also known as the vernal equinox: a time when nearly everyone across the globe gets an even 12 hours of daylight and nighttime hours.

For March in Massachusetts, the forecast favors warmer-than-normal temperatures, and near-normal precipitation.