11 minutes agoLast updated 11 minutes ago
These summer temperatures aren't hanging around for long and spring is about to re-appear.
More than 40,000 runners are taking part in the 26.2-mile event amid temperatures of at least 23.2C (73.7F).
Compare the temperature in your area to other locations in the UK and around the world.
BBC Weather in association with MeteoGroup
All times are BST (Europe/London, GMT +0100) unless otherwise stated.