Chilly Arctic air and potential 65mph winds will see temperatures plummet as the week progresses, leaving Britain feeling "so much different", forecasters warn.

By Thursday, things could be "wintry" in parts of the UK as the mercury struggles to stay in double figures for much of the country.

And despite some sun on Friday, icy winds will leave the temperature feeling even colder, just days after scorching summer-like warmth.

Highs of 13C in London later this week compare to 31C last Monday in a freak plummet, highlighting just how unseasonal the recent heat surges were for mid September.

Multiple weather fronts are queuing up to move in on the UK

If the incoming stormy weather develops enough to prompt amber warnings, the Met Office will name it Storm Aiden as early as tomorrow.

BBC meteorologist Susan Powell said there are some "big changes to come in our weather in the next five days", despite summer having "clung on through the weekend".

"By mid-week it will be much cooler, much windier, and for many, wetter as well.

"The reason for the change - we lose the persistent area of high pressure.

Storm Aiden could be named as early as Tuesday

"That will still be with us for Monday and Tuesday, [but] areas of low pressure will take over from the Atlantic, eventually dragging in Arctic air," she said.

Today begins with mist and fog across eastern Wales and central and eastern England, but this will clear for another warm day as temperatures reach 24C in the south.

But the southwest will see the first signs of an ominous weather front, with showers in the northern and western isles on Tuesday morning slowly encroaching into mainland Scotland.

And while downpours are expected in parts of England and Wales, it will be even hotter than today with London expected to see 25C.

Monday and Tuesday will continue to see sun and highs of 25C

That's thanks to the remnants of Subtropical Storm Alpha, MeteoGroup forecaster Ravi Kotecha has said.

"Midweek is when things really flip," said Ms Powell. "Positioning of our rainfall a little tricky to be precise about at the moment, there are so many fronts in the second part of the week queuing up to come in."

Behind the cold weather front, it will be feeling "noticeably cooler" and another front moving in on Thursday will introduce a northerly wind.

"By Friday, we're all into the Arctic air with a pretty nagging northerly wind - that is going to feel so much different from what we've been used to."

In the highest grounds of Scotland, it could get distinctly wintry by Thursday, while all of the UK will be just about within double figures.

"Further ahead, beyond this week into next weekend it looks quieter once again, but the following week it's still a distinctly autumnal pattern with some wet and windy conditions," added Ms Powell.

The Environment Agency has issued five flood alerts for England today, while Natural Resources Wales has also issued five.

UK 5 day weather forecast

Today:

Fog patches may take until mid-morning to clear from some places, else plenty of warm sunshine. Turning cloudier and windier across northern and western Scotland with some rain later.

Tonight:

Windy in the far north and northwest with rain at times. Dry elsewhere with clear periods and some mist and fog patches forming.

Tuesday:

Dry and warm across much of the UK with fog patches quickly clearing. Band of rain, occasionally heavy, moving southeast across Scotland and Northern Ireland, perhaps reaching northwest England later.

Outlook for Wednesday to Friday:

Turning much colder than recently and unsettled with showers and occasional longer spells of rain. Some drier, brighter interludes are also likely, especially in the west on Friday.