Rain from the Atlantic will hit southern and eastern parts of the country on Sunday, which will also be warm and humid. Forecasters say “tropical” conditions will continue into Wednesday, with temperatures climbing into the 20s. Met Office forecaster Greg Dewhurst told PA news agency: “A changeable picture will emerge over the next few days as it will be on the warm and wet side for many. “Sunday morning looks cloudy, with showers in parts of Wales and central England, with heavy rain falling in southern and eastern England, including London, in the afternoon. “Most of Scotland and Northern Ireland should remain relatively sunny and dry, while temperatures will rise to 27C in parts of England. “It will be warm and muggy and there will be plenty of cloud as high pressure builds on Monday, the day starts sunny and dry before becoming wet and windy in the north-east and west of the UK.” Temperatures in London and the south-east could then reach 29C on Tuesday, before becoming sunnier and cooler from midweek. Mr Dewhurst continued: “There will be a very muggy feeling, more at night, so expect an uncomfortable sleeping time, with temperatures in the late teens.” He said an area of ”tropical sea air” moving in from the south-west would hang over the UK over the next few days. Another meteorologist earlier told the PA “a strange hum can be heard in isolated areas”.