Whether you're one of the estimated 30,000 people running the London Marathon, or supporting someone who is, it's important to know the weather forecast before you go out - you don't want to be cheering on the runners in the rain with no umbrella!
So here's our latest weather update before the big day, to make sure you're fully prepared. Unfortunately it looks like it's set to be quite cool and rainy.
Chris Burton, a meteorologist at The Weather Network, said: "This year’s London Marathon is looking like it will be a soggy one with overcast skies and outbreaks of rain.
"The rain may be fairly light and patchy during the morning before turning heavier into the afternoon.
"Temperatures on the face of it will be fairly mild, reaching 14C into the afternoon, but it will be cooler than recent days and it won’t feel that warm with the moderate southerly breeze and all the rain."
For more London Marathon information, head to our dedicated Marathon page.