October has arrived, and the UK is well into autumn, though the season's start depends on which calendar is followed. The meteorological calendar is consistent year to year, with autumn beginning on September 1 and ending on November 30. Astronomical seasons can differ slightly due to leap years shifting equinox and solstice dates. This year, astronomical autumn began on September 23 and runs until December 20.
Longest day passed, shortest day ahead
Whichever calendar is chosen, the autumn feel is unmistakable across the UK, with leaves changing colour and earlier sunsets. The longest day of the year in terms of daylight, marking the official start of summer, fell on June 21, with days steadily shortening since then. This trend continues until Sunday, December 21, when the winter solstice brings the shortest day of the year.
The clocks go back this month, resulting in brighter mornings but earlier sunsets. Currently in London, the sun sets at around 6.40pm, but as autumn deepens, sunset times will creep earlier.
When the sun sets before 5pm
Londoners can expect the sun to set before 5pm on October 25, the day the clocks go back - one day earlier than the 2025 date of October 26. On that day, the sun is expected to set at approximately 4.46pm.
Sunset times differ across the UK. On October 26, residents of Lowestoft, one of the country's most easterly locations, will see the sun set at approximately 4.37pm. In County Fermanagh, among Northern Ireland's most westerly regions, a sunset before 5pm won't occur until October 30.
Brighter mornings ahead
Wherever in the UK, the evenings are closing in. On the bright side, after the clocks go back, daylight will kick in at roughly 7am instead of 8am.
