GRAND RAPIDS, Mich. (WOOD) — It’s spring! (Astronomical Spring). Today is the Spring or Vernal Equinox. The official start of spring was at 5:24 pm this Monday.

The sun is directly overhead at solar noon at the Equator today.

“Equinox” means “equal night” and on the Vernal and Autumnal Equinoxes, there is equal day and night over the entire Earth. Now, if you see the sunrise and sunset for today (7:46 a.m. and 7:54 p.m. for Grand Rapids), you’ll note that the day is not exactly 12 hours. It’s 12 hours and 8 minutes.

There’s two reasons for that. First, we don’t measure sunrise and sunset from the middle of the sun. Sunrise is when the top tip of the sun first appears over a totally flat horizon. Sunset is when the last or top tip of the sun disappears over a totally flat horizon. The second reason is that light bends a little when it enters the Earth’s atmosphere.

From March 12-26 daylight increases the fastest, at 2 minutes and 56 seconds each day. This week, we’ll gain 20 minutes and 32 seconds of daylight.

Image from the South Pole taken on March 20, 2020

Today, we have (technically) the only sunrise of the year at the North Pole and the only sunset of the year at the Sorth Pole. At the North Pole, we’ll have continuous daylight for the next six months. At the South Pole, it’s the end of summer. However, it’s always “winter” at the South Pole:

The weather at the South Pole Monday evening
Here’s the Difference Between Astronomical Spring and Meteorological Spring

Technically, the coldest 3 months of the year is Dec. 5 to March 5.

Crocuses blooming at the Steffen house.

Read more from Bill’s Blog here.