Britain is forecast to experience "freakishly-hot" temperatures over the next week ahead of Halloween as an "African plume" comes into force.
The autumnal Indian summer is predicted to push the mercury up to 23C and will cap 2022 as the hottest year in Britain that has ever been recorded.
Monday (17 October) is forecast to be the beginning of the warm run, which will last for up to six days, with Wednesday (19 October) predicted to be the hottest day at around 22C.
The South is expected to be warmer than the North, but the whole of the UK should expect sunny spells alongside hot temperatures with some showers.
How long is the hot spell set to last?
Meteorologists have predicted that the mild conditions will last up to Halloween on 31 October.
Netweather forecaster Nick Finnis said: “Some computer models show 22C or 23C by midweek, bringing an Indian Summer. An exceptionally-warm plume of air from northwest Africa looks like being pumped across Europe and to Britain, with up to the low 30s in France, and over 20C in southern Britain.”
MetOffice forecaster Marco Petagna said: “There’s a good signal for higher temperatures thanks to a southerly airstream with very mild or warm air. Sunday has sunny spells for many, with Monday dry with sunny spells in the South as rain clears the North.
“Tuesday is mostly fine in the North, with high pressure from Wednesday bringing generally settled conditions, although with some bands of rain spreading.
“The South and West are likely to be mild during the period to October 28, with sunny spells between showery periods.”
Has it been the warmest year so far?
The plume of warm air from Africa will set 2022 as the hottest year on record for Britain. January to September have already been the hottest first nine months of the year since 1884, when Met Office records began.
Met Office figures for central England show temperatures this month are 1.5C warmer than of previous Octobers.
Dr Mark McCarthy of the Met Office’s National Climate Information Centre said: “It was the warmest year so far up to the end of September, with each month since January being warmer than average.
“2022 is on track to be one of the warmest years on record if warmer-than-average conditions persist.”
Meteorologists had initially forecast a cold spell for the UK as winter approaches, but warmer temperatures are now expected in October as the country basks in an Indian summer.
Weathertrending meteorologist John Hammond said: “It is amazing how a forecast can go so very wrong. The culprit for the chaos is an extremely distorted jet stream, whose exaggerated loops and cut-offs have out-foxed the various computer models in recent days–something we might have to get used to as we head towards winter.
“It had looked as though we’d be heading into a chilly and damp period after mid-month. I now foresee rumours of an Indian summer next week.”