Arkansas Storm Team Blog: Meteorological fall begins Monday

Monday isn’t just Labor Day, it’s also the start of meteorological fall! But what does meteorological fall mean if the fall equinox doesn’t occur until September 22? It’s all about who’s talking about the season and why.

Astronomical fall is what many think of as the official start of autumn. It occurs when the fall equinox happens, which means the Sun is directly over the equator and the Earth isn’t tilted towards or away from the Sun. This causes a nearly equal length of day and night across the globe. This year, the fall equinox falls on September 22. Astronomical seasons are always in accordance with equinoxes and solstices.

Meteorological seasons slightly differ from astronomical seasons. Meteorological seasons are broken up into 3-month increments based on climate and record-keeping. When each season is 3 months long, record-keeping is easier for meteorologists. Meteorological fall begins on September 1 every year.

It’s important to note that astronomy plays the biggest role in seasons on Earth. The reason for seasons is due to the tilt of the Earth. The Earth is tilted 23.5 degrees on its axis. As Earth orbits around the Sun, this tilt causes a change in sunlight throughout the year in each hemisphere of Earth.