Spring equinox heralds start of the season, even if it feels like summer

Spring is here, and even if it may feel to many Americans as if it’s almost over, it actually came a bit early.

With much of the United States basking in near-summer-like warmth, spring officially sprang at 1:14 am Eastern Daylight Time on Tuesday.

Partially due to the leap year, it was the earliest vernal equinox in more than a century. The vernal equinox, which signals the beginning of spring in the Northern Hemisphere and the beginning of fall in the Southern Hemisphere, typically falls on March 21. But this year, in the Mountain and Pacific time zones and points west, spring came as early as March 19.

“Vernal equinox occurs when the sun crosses the celestial equator and night and day are equal,” says Philip Sadler, a Professor at the Harvard-Smithsonian Center for Astrophysics. “It is really just an instance in time.”

“There is no late or early, it is just a matter of the calendar,” he says.

This spring has been exceptionally warm, which has followed a mild winter with little snow.

“It has been a remarkable March across the nation, east of the Rockies,” says Dave Robinson, the State Climatologist of New Jersey and a professor at Rutgers. “Records have been shattered during day after day of warm air.”

Although this warm March has already broken high temperature records, Mr. Robinson cautions that there is still a week left of the month.

The unusually warm winter and spring may make climate change feel more like a reality, but according to Robinson, it is only one piece of the puzzle.

“It still would have been a warm March without humans because of the jet stream being positioned further north than usual. Human influence may have contributed, but it is still too early to tell,” he says. “But when you look at the big picture, snow coverage is leaving earlier and there has been a trend of increasing warmth in the past few years.”

The spring equinox is being marked with celebrations around the world this week.

In Iran, Nowruz, the Persian New Year, is celebrated on the vernal equinox with spring-cleaning, visits to family and friends, and traditional foods.

President Obama used the holiday as an occasion to address Iranians.

“To the people of Iran, this holiday comes at a time of continued tension between our two countries. But as people gather with their families, do good deeds, and welcome a new season, we are also reminded of the common humanity that we share,” Mr. Obama said in a video message.

In Japan, shunbun no hi, or Spring Equinox Day, is observed by visiting graves and worshiping ancestors.

In England, Vernal equinox revelers hiked to Stonehenge at dawn to celebrate among the 5,000-year-old monument’s stones.

In a more recent tradition (it dates back to the 1980’s), residents of Annapolis, Md., burn their socks on the vernal equinox in celebration of the end of sock-season.