Soon after the autumn equinox, colder air plunged into central and eastern Europe. The first snow fell in the Tatra mountains, the Alps and the Tyrol. The heatwave was swept out of southeast Europe - it looked like the arrival of autumn.

Northern Europe has been an often windy place since, and the temperatures have varied wildly. But one element that brings in colour has been rare. Frost is a necessary component in turning leaves into golden hues that prove the change of season.

Indeed, much of Europe is even now seeing a resurgence of heat, removing any likelihood of night-time frost. As a result, many trees have still to realise that they should no longer be green.