'Perfect conditions' for London Marathon
22 April 2012 Last updated at 07:50 BST
Organisers of the Virgin London Marathon have said the weather for the 26-mile race are 'almost perfect' for runners.
The race starts at Greenwich Park and ends at the Mall, with the elite women's group going first.
Race Director Dave Bedford praised the 6,500 volunteers who work to keep the huge event running smoothly.