As the temperature drops and foliage changes color, it’s evident that summer is coming to an end. This transition also marks the arrival of the annual autumn equinox, scheduled for next Monday, September 22.

The autumn equinox officially ushers in the fall season for the Northern Hemisphere, where day and night are nearly equal in duration. Following this event, the Northern Hemisphere will experience longer nights than days, while the Southern Hemisphere will see longer days.

Dr. Shyam Balaji, an astrophysics expert from King’s College London, highlighted the significance of the September equinox. He explained that on September 22 at 18:19 UTC, the tilt of Earth’s axis aligns to provide both hemispheres with almost equal hours of daylight and darkness, signaling the onset of autumn in the North and spring in the South.

The Earth’s orbital movements around the Sun are responsible for the changing seasons. Equinoxes, like the autumn equinox, occur when the Sun illuminates both hemispheres equally, indicating the beginning of spring or autumn.

In contrast, solstices occur when Earth’s tilt maximizes its exposure to the Sun, marking the start of summer or winter. These celestial events have been observed and understood by early humans, who used the Sun to track time and comprehend the seasonal shifts we recognize today.

According to the Met Office, astronomical autumn this year will span approximately three months, concluding on Sunday, December 21. The autumn equinox signifies the Northern Hemisphere tilting away from the Sun, leading to shorter days and cooler temperatures as the region transitions towards winter.

Despite longer nights approaching, the UK will revert to Greenwich Mean Time on October 26, gaining an extra hour as clocks are set back at 2 am. Daylight saving time aims to optimize daylight usage during summer months, with clocks changing to maximize daylight hours.

The ongoing debate around daylight saving time revolves around its impact on energy consumption, outdoor activities, and road safety. While some argue for its benefits, others raise concerns over darker mornings and potential inconveniences.

The UK will remain on GMT until March 29, 2026, when clocks will shift back to British Summer Time. Devices connected to the internet will automatically adjust to the time change, but the Government provides a list of future clock adjustments for those who wish to manually update their calendars.