Stonehenge in the summer sunshine

When does summer start?

Astronomical summer

The astronomical calendar determines the seasons due to the 23.5° tilt of the Earth's rotational axis in relation to its orbit around the Sun. Both Equinoxes and Solstices are related to the Earth's orbit around the Sun.

This year, astronomical summer began on the 21st of June 2019 and ended on the 23rd of September 2019.

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

Year Summer Starts Summer Ends
Summer 2019 Friday 21st June 2019 Monday 23rd September 2019
Summer 2020 Saturday 20th June 2020

Tuesday 22nd September 2020

Summer 2021

Monday 21st June 2021

Wednesday 22nd September 2021

Summer 2022

Tuesday 21st June 2022

Friday 23rd September 2022

Summer 2023

Wednesday 21st June 2023

Saturday 23rd September 2023

Summer 2024

Thursday 20th June 2024

Sunday 22nd September 2024


Meteorological summer

However, meteorologists are also interested in the beginning of the meteorological summer. Meteorological summer will always begin on the 1st of June; ending on the 31st of August.

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. 

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

Solstices and equinoxes

Solstices and equinoxes are the astronomical transition points between the seasons and mark key stages in the astronomical cycle of the Earth. In a year there are two equinoxes (spring and autumn) and two solstices (summer and winter). The dates of the Equinoxes and Solstices aren't fixed due to the Earth's elliptical orbit of the Sun. The Earth's orbit around the Sun means that in early January, the Sun is closest (known as perihelion) and in early July it is most distant (aphelion).