Break out the sweaters and warm drinks—autumn has officially begun. The fall season kicks off in the Northern Hemisphere at 2:19 p.m. EDT today, Monday, September 22, with the arrival of the autumnal equinox.
The equinox occurs twice a year, in March and September, when the tilt of the Earth’s axis aligns so that neither hemisphere leans toward or away from the sun. At that moment, the sun appears directly above the equator, signaling the shift into a new season. In September, this marks the official start of fall.
While many people consider summer to have ended weeks ago, that depends on the calendar being used. Meteorological summer runs from June through August, meaning it wrapped up August 31. Astronomical summer, however, stretches until the equinox, giving summer a few extra weeks each year.
One of the most common misconceptions about the equinox is that day and night are exactly the same length. While they come close to even, the precise balance—known as the “equilux”—doesn’t arrive until a few days later and varies by location.
Across much of the country, signs of the season are already taking hold. In northern states, leaves are beginning to change, with vibrant foliage expected in New England in the coming weeks. Cooler mornings are settling in, inviting cozy scarves, blankets, and, for many, the annual return of pumpkin spice.
Source: The Weather Channel