Why isn't it officially fall until 1:02 p.m. today? It's a good question, and it has to do with the way the sun's rays strike the Earth.
Around the world we mark the equinox as the date when day and right are equal/almost equal at all latitudes, but the equinox itself isn’t all day long.
It’s a specific point in time when the sun's vertical rays strike the equator. This happens when the sun is positioned directly over the equator, and Earth is tilted neither away nor towards the sun.
So the time of the equinox isn’t arbitrary at all. In the case of the 2017 autumnal equinox, fall begins at 1:02 p.m. Tomorrow is actually the first full day of fall, even though astronomically speaking, the season starts this afternoon.
In an effort to track weather and climate more accurately, meteorologists define fall as September-October-November. So in my world, it’s been autumn since September 1.
Bring on the pumpkin spice lattes! Just kidding. I’m still not ready to say goodbye to summer.
