Met Office forecasters are predicting a chilly start but a mainly dry day on Sunday for the Marathon.
There should be plenty of sunshine through the morning and temperatures are expected to rise to around 14 or 15 Celsius by mid-afternoon. It will become increasingly cloudy through the afternoon though and occasional rain is possible over London by late afternoon or early evening. Winds will be light and south-westerly throughout the day.
The latest forecast, information about the course and past weather can be found online via the London Marathon pages. As always, you can stay up-to-date with the latest weather for the rest of the UK UK forecast, through our Weather services, Facebook, Twitter and through TV and radio broadcasts.