This Sunday's London Marathon could be the warmest on record, with temperatures expected to peak as high as 23°C.
According to Met Office records, the warmest marathon was in 1996 when temperatures at St James's Park reached 22.7°C. Tomorrow morning is likely to start off humid and remain hot throughout the day, with temperatures expected to reach at least 22°C, if not 23°C.
Met Office chief meteorologist Will Lang said: “For those running the marathon, make sure you stay up-to-date with the forecast as there will be high temperatures and humidity to contend with. Stay hydrated and listen to advice from the event organisers.”
The warm weather conditions have prompted warnings from the marathon's medical director Professor Sanjay Sharma that those considering the traditional fancy dress option may have to ditch their grand plans.
"In the conditions forecast for Sunday, you should slow your planned pace. If you were planning to run in fancy dress, please think carefully whether that is still appropriate in the conditions," he said.