Brits could be relaxing in warm weather brought up from southern Europe by the weekend, forecasters say.
A burst of unseasonably warm weather for the end of October will send the mercury up to 21C in the capital and parts of the south east on Saturday, according to BBC Weather.
Warmer than usual conditions are also expected in other parts of the UK from Thursday onwards, reaching the high teens in many areas.
Met Office meteorologist Aidan McGivern told LBC that this was down to a plume of warm air from the Azores being sent north by the jet stream.
He said: "What we've got during the next few days is the jet stream coming out of North America, and then strengthening on the other side of the Atlantic because of this temperature contrast between north of the jet stream and south of the jet stream."
"Then, the jet stream dips close to the Azores before pushing north again during Wednesday, Thursday, Friday and the weekend as the warm air pushed north across Europe.
"It will be unusually warm for much of the continent, not just the UK."
Despite the warm outlook for the end of the week, a number of flood advisories are in place on Wednesday morning following several days of changeable weather.
One flood warning is in place by the Environment Agency across England, along with eight lesser flood alerts where 'flooding is possible.'
UK weather:
Unsettled and very mild, sometimes wet and windy in west.
Today:
Cloud and outbreaks of rain, some heavy, moving north but likely becoming brighter with some sunny spells developing through the afternoon in the south. Windy in the far north at first. Very mild, especially in the southeast.
Tonight:
Rain, heavy at times, with coastal gales developing across the far southwest and moving north overnight, although northern Scotland and eastern England remaining dry. Very mild.
Friday:
Rain, heavy at times accompanied by strong winds clearing northeast with sunny spells following. A few showers developing across Northern Ireland in the afternoon. Mild.
Outlook for Saturday to Monday:
Staying unsettled and very mild. Heavier rain and strong winds always more likely towards the west with some drier, brighter interludes especially in the east.