SNOW has hit parts of the UK today - as the mercury plummets a whopping 10C this week and rain batters the west.
Hill-walkers were caught off-guard as blizzards hit mountaintops in Scotland - with many saying it's unusually early for such chilly weather.
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Snow has fallen on Scottish mountaintops - as the temperature drops across the UK Credit: Deadline 5
Far more autumnal seasons are expected into October
And forecasters say autumn has well and truly arrived as our gorgeously warm Indian summer comes to a blustery end.
Last Tuesday, the mercury hit a scorching 25.3C in London. Today, it'll struggle to reach 16C.
And temperatures dropped as low as 3.2C at Redesdale Camp in Northumberland in the early hours of this morning.
Meteorologist Simon Partridge of the Met Office said Wednesday will be the "best day of the week", with lots of sunshine predicted and highs of 15C.
"The word 'unsettled' definitely covers it this week," he said.
"It's going to be very autumnal.
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"At this time of year, our average maximum temperature for south-east England is only about 17 or 18C, so it's really about where we should be.
"We've got used to temperatures being higher than they usually are - we've just come back to reality."
His colleague Aidan McGivern said much of September was a "long period of late summer".
"This week will feel much more autumnal," he said.
"With Atlantic weather now in charge, we can expect very changeable weather through the week.
"There'll be wind and rain, but also showery and sunnier periods at times."
The west is set to see some of the worst of it, with "lively weather" predicted, including "a chance of some hail and thunder in some places".
'IT'LL BE LIVELY'
Over the course of the coming days, there'll be a series of weather fronts happening one after the other - and each will drag in rain and wind, he said.
"Into Tuesday evening, the wet weather transfers its way eastwards associated with this weather front," he said.
"It'll start to interact with the jet stream, which picks up this weather front and deepens it into a fairly vicious low as it crosses the UK."
The east could see coastal gales tonight.
Tomorrow, there'll be showers around the country - particularly in the west - with the best of the weather in the south and east.
Towards the evening, the "next low comes quickly trundling along", Mr McGivern said.
"That's going to bring some steadier rain in for start of Thursday, with some heavy and persistent rain across the north and west," he added.
'VICIOUS LOWS'
"Thursday night then picks up the next system. There's a risk of coastal gales on Thursday night into Friday, and a spell of fairly heavy rainfall crossing the UK early on Friday.
"It's likely to be a narrow band but it could be fairly lively feature as it pushes through, finally clearing by the afternoon to sunny spells and showers."
The weekend is set to be just as blustery, he warned.
Yesterday, a suspected tornado wrought a path of devastation in Hull.
A huge campervan overturned into a bungalow, causing massive damage, while tiles were ripped from roofs and fences were torn down.
Heavy downpours caused flash floods.
It's a far cry from the stunning late-summer sunshine of last week, when the UK was warmer than Lisbon.
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Yesterday, a bizarre mini tornado touched down in Hull, overturning a campervan onto a bungalow Credit: Ben Lack 5
Flash flooding in Swansea left a Mercedes stranded Credit: Robert Melen 5
The west is set to see the worst of the weather, forecasters say Credit: joshuabratt1@hotmail.co.uk
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