Weather maps show the UK will reach extreme temperatures of 36C (96.8F) on Wednesday, July 29, making four areas hotter than Greece, which is forecast 35C (95F).
Areas hotter than Greece
The four areas expected to exceed Greek temperatures are Greater London, Surrey, Berkshire and Buckinghamshire.
Hertfordshire and Cambridgeshire are forecast highs of 35C, matching the Mediterranean country. Sussex is also predicted a scorching 35C.
Heatwave into August
The Met Office warns that conditions could turn "very warm again by the start of August." If temperatures continue into August, an official heatwave will be announced.
A heatwave is defined as a prolonged period of excessively hot and humid weather, lasting three or more days, relative to the normal climate of a specific location.
Other areas
Cooler parts of England on July 29 are still expected to reach around 30C. Yorkshire will see 30C, Greater Manchester 31C, while the south west may be slightly below 30C.
The Met Office forecast for the period says: "A changeable period is likely overall, with many areas likely to see a mixture of bright or sunny spells and some rain at times. Temperatures will be near or above normal, warmest in the south, and perhaps becoming very warm again by the start of August."
Following previous heatwaves, if these highs are reached, disruption could be felt across the nation. In June, records were broken and chaos erupted in both transport and healthcare departments.
