The Met Office has stated that Essex could see the hottest day of the year so far - with temperatures higher than Honolulu, Madrid, and Los Angeles.
Forecasters have said that the temperature in the county could exceed the 27C recorded in Fife in Scotland this year.
But the day could prove miserable for hay fever sufferers, with pollen levels also predicted to be among the highest of the year.
Helen Roberts, forecaster at the Met Office, said: "It will be a very hot day.
"We think that temperatures could go higher in areas North East of London towards the East Anglia region.
"We know that there is cloud further north but East Anglia, with a light south west wind, could exceed 27C."
The previous high in Essex, 26.5C was recorded on June 9 and 10 in Writtle.
