It almost feels like summer never really arrived… and now autumn officially begins today! Get ready for nights to draw in and leaves to begin falling.

You may be thinking that autumn doesn't start until later in September, and you wouldn't be wrong thinking this. There are two separate dates which can be used to define the start of the season.

Astronomically, the start of autumn takes places on the autumn equinox, when the length of day and night are the same in all parts of the world. It is defined by the Earth's axis and orbit around the sun, and the exact date varies slightly each year.

This year, the autumn equinox falls on September 23 at 07:49 am BST, with the astronomical autumn running until December 22.

For meteorologists in the Northern Hemisphere, autumn beings on September 1. It is a fixed date because it is statistically easier to process the data by taking four equal quarters for each of the four seasons. The meteorological spring is made up of March, April, and May.

While the days are really getting shorter and cooler for us, the opposite is true for those in the Southern Hemisphere. For them, today marks the start of the meteorological spring.

Learn more about our seasons in our weather explained video here: