Vernal Equinox

In my book, spring started a few weeks ago on March 1, with the onset of Meteorological Spring. Many, however, would say that today is the first day of spring, as it is the Vernal Equinox.

The reason that we have equinoxes is because of Earth's tilt, which is a 23.5° tilt. As Earth orbits the sun, it receives direct sunlight at different portions of its sphere at different times of the year. At the Vernal Equinox (which can be thought of as a position on Earth's orbit), the equator receives direct sunlight at solar noon. Likewise, that is the case on the Autumnal Equinox.

(NWS)

In the above image, notice how the tilt of the Earth is responsible for why we have solstices and equinoxes (and season). Different latitudes receive the most direct sunlight at different time of the year.

Thankfully, the varying nature of the sunlight that we receive at different times of the year gives us exciting, variable weather to talk about.

Enjoy the warmer weather this weekend!