Have you ever asked yourself, when does Spring actually start? Or why there are two different ways of determining the actual date of Spring’s first day?
Generally, the Spring season starts on two different dates. Its date can vary from year to year, depending on whether you’re using the astronomical or meteorological definition of the seasons.
However, due to the changing and unpredictable weather and temperatures in the UK, it can be difficult to decipher when Winter ends and when Spring officially begins. For today’s write-up, our experts have listed down everything you need to know about spring.
When Is Spring 2019?
If you are using the meteorological definition of the seasons, spring 2019 officially starts on the Friday March 1st, Friday. However, the astronomical definition states that the first day of spring starts on Wednesday March 20th.
Meteorological vs Astronomical Spring
The meteorological definition of the seasons splits the year into four seasons of three full months. This is based on the Gregorian calendar.
By using this definition, it will be easier for you to compare seasonal and monthly statistics. In meteorological spring, the spring season begins on the 1st of March and lasts until the 31st of May—with summer beginning on the 1st of June.
On the other hand, the astronomical spring depends on the date of the spring equinox—also known as the vernal equinox or March equinox that varies year to year.
Whilst the astronomical calendar calculates the seasons depending on the 23.5-degree tilt of the Earth’s rotational axis in relation to its orbit around the sun.
How Equinoxes Work?
The word “equinox” derives its name from the term “eqi” which is a Latin term that means “equal” and “nox” means “night”. According to the astronomical calendar, when the day and night are roughly 12 hours each everywhere on Earth—there will be two equinoxes each in a year in March and September.
This marks the only two points in the year when the celestial equator, an imaginary projection of the Earth’s equator, is the closest part of Earth to the sun.
The spring equinox consists of four days during the year that marks the beginning of a new season:
- two equinoxes
- two solstices
The spring equinox officially begins when the winter time ends and springs begins in the Northern Hemisphere. This 2019, the spring equinox will fall on the 20th of March, Wednesday. However, it can vary between the 19th, Tuesday, and the 21st of March, Thursday.
The astronomical spring will last until the 21st of June, Friday before the summer solstice starts on Saturday, June 22. The autumn gives way to winter on the date of the winter solstice that falls on the 21st of December, according to the astronomical system.