According to BBC Weather, the capital will bask in highs of between 26C and 28C from Saturday, June 13 to Wednesday, June 17.
A heatwave is declared in London when the temperature reaches 28C on three successive days.
The predicted highs are slightly warmer and spread over a longer period than BBC Weather was forecasting next week, suggesting the chances of an imminent heatwave in London are strengthening.
It may seem hard to believe a hot spell is so close as millions in London trudge to work through the rain this week.
BBC Weather is predicting four days of wet weather with temperatures topping out at 17C-19C, before conditions turn better on Friday.
Met Office forecaster Craig Snell said the weather is expected to settle by the weekend and “could potentially feel markedly warmer”.
Many will be hoping predictions of a hot summer come turn out to be accurate after a record-breaking May heatwave.
A high of 35.1C was provisionally measured at Kew Gardens in London on May 26, a new record for the month of May, while temperatures topped 30C six days in a row in some areas.
Amber heat-health alerts were issued for several regions of England, meaning conditions were a risk to vulnerable people and likely to put pressure on health services.
The heatwave meant England and Wales ended up having their warmest spring on record this year.
The mean average temperature in England across March, April and May was 10.41C, beating the previous record of 10.23C set in 2025, according to provisional figures from the Met Office.
It is the third year in a row that a new record has been set for the warmest spring in England.