Your daily UK weather forecast 20 October 2021 for London.
London is currently in Autumn. Perhaps the most noticeable sign of autumn in the UK is the changing colours of the leaves. As a result of the falling temperatures in autumn, the chemical in the leaves that makes them green (chlorophyll) begins to break down while other chemicals (including carotene) remain to give the leaves their yellow, red and brown colours.
The most vibrant displays of autumn leaves are evident when a dry summer is followed by an autumn with dry, sunny days and cold, but not freezing, nights.
Autumn according to the meteorological calendar begins in September and ends in November. In the astronomical calendar, the beginning of autumn is marked by the autumn equinox which occurs around the 22 September.
During the autumn equinox, the Sun shines directly on the equator and day and night around the globe are of almost equal length – a day and night of roughly 12 hours each.
Autumn is normally associated with dropping temperatures and the nights drawing in as winter approaches. In the UK autumn can often bring unsettled weather and towards the latter part of the season can often bring stormy conditions with strong gales due to Atlantic depressions moving over the UK.
Patchy rain should clear through the morning, leaving a drier and brighter spell in the afternoon before further heavy rain arrives later. Very mild. Maximum temperature 19 °C.
None.
Low.
Flood alerts in force for England.
>10%
Weather data provided by the Met Office. For a detailed forecast of your area, click here.
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