20 March 2021 = vernal equinox 2021
The first day of Spring! Yippee!
Well, the astronomical Spring. We’ve actually been in meteorological Spring for the past 20 days, since 1 March!
Meteorological seasons are split into four equal periods of three months each – so meteorological Spring always starts on 1 March and ends on 31 May.
However, today’s first day of Spring is the astronomical Spring. This is defined by when the Earth’s tilt and rotation around the sun causes the length of the day and night to be equal. Owing to such things as the shape of the Earth (it has a bulge around the equator) the exact timing of the equinox phenomenon varies from year to year. This year, in the northern hemisphere, we should experience the vernal equinox around 9:37am on 20 March 2021.
Looking out of my window, I can see that today is a beautifully sunny day.
As I say to my granddaughters, “Let’s see what we can see…”