When does spring start?

How you define the first day of spring depends on whether you are referring to the astronomical or meteorological spring, says the Met Office. 

Astronomical spring

Astronomical seasons refer to the position of Earth’s orbit in relation to the Sun, considering equinoxes and solstices.

This is due to the 23.5 degrees of tilt of the Earth’s rotational axis concerning its orbit around the Sun.

Since the seasons vary in length, the start date of a new season can fall on different days each year.

This year, astronomical spring began on 20 March 2019 and ended on 21 June 2019.

For upcoming years, the dates for astronomical spring will be;

Meteorological spring

Meteorological seasons are instead based on the annual temperature cycle and measure the meteorological state, as well as coinciding with the calendar to determine a clear transition between the seasons.

The meteorological seasons consist of splitting the seasons into four periods made up of three months each.

These seasons are split to coincide with our Gregorian calendar, making it easier for meteorological observing and forecasting to compare seasonal and monthly statistics.

By the meteorological calendar, spring will always start on 1 March; ending on 31 May.

The seasons are defined as spring (March, April, May), summer (June, July, August), autumn (September, October, November) and winter (December, January, February).

Content courtesy of the Met Office