UK's hottest day of year to date forecast – but record won't last long

Temperatures could exceed the 20.3C recorded on 21 April, and will carry on rising through the week to as high as 27C

Britain is expected to enjoy the hottest day of the year so far on Thursday but air pollution is forecast to accompany the warm weather.

Defra, the department responsible for official pollution warnings, said moderate air pollution was likely in much of England and Wales and urged people with lung or heart problems who experience symptoms to consider reducing strenuous physical activity, particularly outdoors.