What is a false autumn and why are we experiencing one?

As leaves turn brown, evenings darken and pumpkin spice lattes return, it may feel like autumn has arrived.

But the first official day of autumn is not until 22 September, so what is happening?

Experts at the University of Worcester say it is down to a phenomenon called false autumn, where trees and plants behave as if the season has changed due to the stress of extreme summer conditions.