With the threat of flash flooding looming large, property owners face the prospect of having to turn to their home insurance provider if their properties become inundated.
The Environment Agency and Met Office has already issued flood alerts for various parts of country, as heavy rain and thunderstorms are predicted following the heatwave.
Heavy rainfall and hail storms have been forecast for London, the South East and eastern England in the space of a few hours.
With up to 30mm of rain predicted, rivers in the London Boroughs of Lewisham, Bromley, Greenwich and Croydon could overflow, the Environment Agency said.
The areas hit by heavy storms could also witness surface water flooding.
"Environment Agency staff are on 24-hour alert and teams are monitoring river levels as the band of rain moves across the country. The public is encouraged to tune in to local media for weather forecasts for their area and to keep an eye out for signs of surface water flooding," an Environment Agency spokesman said.
© Press Association 2011