when is autumn 2023

Autumn 2023 in the northern hemisphere ran from September to December 2023, with two common ways of defining its dates:

• Meteorological autumn 2023 :
  • From 1 September 2023 to 30 November 2023.

• Astronomical autumn 2023 (by the equinox and solstice) :
  • Started around Friday 22 September 2023 in North America (late evening Pacific time).

* Often taken as starting on Saturday 23 September 2023 at 6:50 am GMT in UK-focused sources.

* Ended around Thursday 21 December 2023, when the winter solstice marked the start of winter.

So, if you go by the weather/calendar system, autumn 2023 was September–November, but if you go by the Sun’s position (equinox to solstice), it was roughly late September to 21 December 2023.