The groundhog got it right this year. Spring came early. In fact, March 19 is the earliest date it has arrived in the past 124 years.
Not to discredit the famous groundhog, but some experts claim spring began even earlier, on March 1.
Exactly when the season started depends on whom you ask. An astronomer will tell you that spring officially arrives at 8:49 p.m. Thursday. But a meteorologist will say spring arrived more than two weeks ago.
Why the difference?
Astronomical seasons are based on the position of the Earth in relation to the sun. For scientists who study the planets, stars and other not-so-earthy objects, the first day of spring is determined by the vernal equinox, when the amount of daylight and darkness are almost equal. This typically occurs March 20 or 21 in the Northern Hemisphere – so yes, it’s taking place early this year. There are two equinoxes annually, one in March and the other in September, and their occurrence is determined by the elliptical shape of the earth’s orbit around the sun and leap years.
In contrast, the meteorological seasons are more straightforward, beginning and ending on the same dates each year. Each season consists of three consecutive months based on the civil calendar and the annual temperature cycle. This being the case, meteorological spring runs March 1 to May 31; summer is June, July and August; autumn runs September, October and November; and meteorological winter falls on December, January and February.
Because astronomical seasons vary in length from 89 to 93 days, the unvarying meteorological seasons were created to allow scientists to better compare monthly data and observe and predict weather patterns from year to year.
Thursday’s start of astronomical spring is occurring almost 18 hours before it did in 2019. And talk about early – the previous time it fell on March 19 was in 1896.
Sure, we’d like to give all the credit to Punxatawney Phil, who didn’t see his shadow on Feb. 2. But astronomically speaking, spring’s early arrival has more to do with how long it took for the Earth to revolve around the sun and our 2020 leap year.
In the meteorological world, spring began March 1, the same date it has since the mid-1900s when the seasons were differently defined.
Either way, spring is here. Besides budding trees, returning geese and more daylight, what will the season bring? If the record snowfall and unseasonably cold temperatures that dropped into the teens last weekend are any indication, perhaps these words by 20th century author Henry Van Dyke sum it up best:
“The first day of spring is one thing, and the first spring day is another.”
Nic Loyd is a meteorologist in Washington, Linda Weiford is a writer in Moscow, Idaho, who’s also a weather geek. Contact: email@example.com.
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