UK Weather,
A woman films her four-legged friend as they both swim in the April waters of Newquay Harbour, Cornwall, UK
The Met office predicts for the South, "21C to 22C (72F) temperatures are quite likely in places on Thursday or Friday, and "23C (73F) is just about possible".
That means it's also "quite likely" this week will see the highest temperature of the year so far, possibly beating the 21.3C recorded at both Northolt and Chertsey on 20 March.
The dry sunny weather comes with a warning for allergy sufferers, though, as he predicted pollen counts "will reach moderate in much of the South, while air pollution spreading from the near continent will raise levels to moderate for many southern parts on Friday".
Parts of the UK could be hotter than cities in Greece and Spain this week, as the country continues to bathe in spring sunshine.
Dry, sunny conditions could see temperatures rise as high as 21C (70C) on Thursday in the south of England, while Athens is set to peak at 17C (63F), the Met Office has said.
South Wales and Somerset could reach 20C (68F) and may be hotter than Barcelona, where 16C (61F) is the expected high.