Met Office temperature maps show 20 counties across the south, east and Midlands of England will get at least 22C at around 4pm tomorrow, with 14 areas mainly around London and the east of England forecast to enjoy 23C.
Tom Morgan, Met Office meteorologist, said temperatures for many central and eastern parts of England will be "5-7C above average" through the afternoon tomorrow. He described the high temperatures as "unusual warmth", adding that they will "generally be above average for the time of year".
Warm spell continues into next week
The above-average temperatures follow a mild weekend that saw many parts in the south and east of England enjoy up to 22C. The warm weather is set to continue into next week, with temperatures even going up to 23C tomorrow afternoon.
Mr Morgan said: "The south is set to stay unusually warm through the next few days." Giving an outlook for tomorrow, he added: "Sunny spells developing quite widely for central southern England, perhaps South Wales as well and certainly across to more eastern parts of England so another warm day for October here."
Rain and wind for northern areas
Further north, a band of cloud and some outbreaks of rain will push southwards, clearing away from northern Scotland, with a wet picture for Northern Ireland by the afternoon. Sunny spells and a few blustery showers are expected for northern Scotland by that point.
Mr Morgan noted that winds will gradually ease down for many northern areas but stay very windy in the far north of Scotland, with gales continuing for Shetland and Orkney. The north, compared to the south of the UK, "has a much more autumnal feel", with temperatures "a little bit closer to the average in the very far northwest of Scotland".
Areas forecast to reach 23C and above
The 14 areas due to get 23C tomorrow afternoon are Maidstone, Hounslow, London, Sudbury, Ipswich, Framlingham, Stowmarket, Cambridge, Halesworth, Huntingdon, Ely, March, Feltwell and Stamford.
The full list of counties with 22C or above on Monday afternoon includes Kent, Surrey, London, Hampshire, Berkshire, Wiltshire, Buckinghamshire, Oxfordshire, Essex, Cambridgeshire, Leicestershire, Warwickshire, Worcestershire, Northamptonshire, Suffolk, Norfolk, Lincolnshire, Bedfordshire, Dorset and Hertfordshire.
