Ayr is losing more than four minutes of daylight every day as autumn arrives

Residents in Ayr are seeing the long summer evenings disappear at a striking pace, with the town and wider Ayrshire currently losing around four minutes and 25 seconds of daylight every day.

At the start of September, the sun rises in Ayr at approximately 6.22am and sets shortly after 8.15pm, giving the town just under 14 hours of daylight. By the end of the month, sunrise will be around 7.19am and sunset approximately 6.57pm.

That change leaves Ayrshire with only 11 hours and 38 minutes of daylight by the end of September — a loss of roughly two hours and 15 minutes in a single month.

How quickly daylight is disappearing in Ayr

The reduction is equivalent to approximately 31 minutes of daylight each week. Since the summer solstice, Ayrshire has already lost about three hours and 35 minutes of daylight. Between the longest and shortest days of the year, the total difference is around 10 hours and 25 minutes.

• Each day: around four minutes and 25 seconds less daylight
• Each week: approximately 31 minutes less daylight
• During September: around two hours and 15 minutes less daylight
• Since the summer solstice: approximately three hours and 35 minutes less daylight
• Between the longest and shortest days: around 10 hours and 25 minutes

The evenings are changing more noticeably than the mornings. During September, sunset in Ayrshire moves from shortly after 8.10pm to before 7pm, while sunrise shifts from around 6.24am to approximately 7.19am. Sunset is moving earlier by roughly two-and-a-half minutes each day.

When does autumn begin?

Autumn has more than one recognised starting point. Meteorological autumn begins on September 1 and runs until November 30. The fixed dates are used by weather experts to make seasonal statistics easier to compare.

Astronomical autumn begins at the autumn equinox, which this year occurs at approximately 1.05am on Wednesday, September 23. The equinox takes place when the Sun crosses the celestial equator and illuminates the northern and southern hemispheres almost equally.

There is also phenological autumn, which is identified through changes in nature rather than a fixed date. Those signs include leaves changing colour, berries ripening, birds migrating and the first leaves beginning to fall.

Despite the name equinox coming from Latin words meaning “equal night”, daylight does not last exactly 12 hours on the equinox. Atmospheric refraction allows people to see the Sun briefly before it has physically risen above the horizon and after it has technically set.

The point when daylight and darkness are closest to being equal is known as the “equilux”. In Scotland, that normally occurs a few days after the autumn equinox.

What happens next as the clocks change?

British Summer Time ends on Sunday, October 25, when the clocks go back by one hour. The change does not alter the actual amount of daylight, but it moves an hour of available light from the evening to the morning. In Ayr, sunset on October 31 will be approximately 4.41pm.

The shortest day arrives on Monday, December 21. Around the winter solstice, Ayr will have only about seven hours of daylight, with sunrise close to 8.45am and sunset shortly before 3.50pm.

The earliest sunset and latest sunrise do not occur on the solstice itself. In Ayr, the earliest sunset comes around December 14, while the latest sunrise is around December 29. This happens because of the Earth’s orbit and the way clocks measure a standard 24-hour day.

The darker evenings can also bring a seasonal opportunity. The weeks around the autumn equinox can improve Scotland’s chances of seeing the Northern Lights, as geomagnetic activity tends to be stronger around the spring and autumn equinoxes and the country benefits from increasingly dark skies.

Nature is already responding to the seasonal shift. Shorter daylight and cooler temperatures cause deciduous trees to reduce chlorophyll production, allowing yellow, orange and red pigments to become visible. Late August and early September are also prime times for blackberries, while rowan berries, elderberries, rosehips, sloes and hazelnuts become increasingly noticeable.

Swifts and swallows begin travelling south, while redwings, fieldfares, geese and several species of duck are due to arrive in Scotland from colder parts of Iceland, Scandinavia and northern Europe.

Summer is not disappearing overnight, but the change in Ayr will become increasingly obvious throughout September as the town loses roughly half an hour of daylight every week.