I just found out that the spring equinox in the United States recently passed. It turns out that when it's spring in the United States, March 20th was exactly at 10:46 a.m. (Eastern Time). The interesting thing is that day and night were almost the same length at that moment because the Sun crossed the Earth's equator precisely, and the Earth's axis was neither tilted toward nor away from the Sun. Basically, it's the perfect balance point of the year.

What surprised me is that the equinox doesn't always fall on the same day. It can be between March 19 and 21 depending on the year and calendar adjustments. So, when it's spring in the United States, it's not a fixed date, although most years it's on the 20th. From that moment, the hours of sunlight started gradually increasing until the summer solstice in June, when summer begins. That explains why after March, the days get longer and temperatures rise progressively.

Additionally, I read that astronomical spring is different from meteorological spring. Astronomical spring is based on Earth's position in its orbit, while meteorological spring follows the Gregorian calendar and climate patterns. In 2026, northern spring will last about 92 days, from March 20th until June 20th or 21st. There are regions where the climate has already warmed up since the first weeks, but in others, late cold fronts could still occur. It's interesting how, when it's spring in the United States, the weather varies so much depending on where you are.