Equinoxes occur when Earth reaches a point in its orbit where the sun shines directly on the equator. This happens twice a year, in March and in September, and is a result of Earth’s spinning on an axis that is tilted 23.5 degrees from the plane of its orbit.

In Japan, Autumnal Equinox Day is a national holiday. In Japanese, it’s known as Shubun no Hi (秋分の日), according to Coto Japanese Academy. The roots of the celebration are thought to go back to Shintoism and Buddhism.

The equinox has no relationship to Houston’s weather, and the city’s climate afterwards isn’t guaranteed to bring cooler or warmer temperatures.