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London Marathon

Chilly but fine



The 2017 Virgin Money London Marathon takes place on Sunday 23rd April. The London Marathon was first run in 1981 and has since grown to become the third largest running event in the UK, after the Great North Run and the Great Manchester Run. Last year over 40,000 runners started the event.

The weather conditions on the day can have a big impact on performance. Research suggests the performance of runners in marathons decreases as the wet bulb temperatures increase from 5C to 25C. Higher wet bulb temperatures indicate more humid air.

What's the London Marathon weather forecast looking like this year? 

By Chmee2 (Own work) [CC BY-SA 3.0], via Wikimedia Commons

Latest weather forecast

Computer models suggest dry but chilly weather on Sunday morning in London. High pressure is expected to be centred over western parts of the UK. Arctic air will be plunging down its eastern flank, but the core of the cold is likely to be over the North Sea.

The GFS12z chart below shows forecast rainfall for 09:00GMT on Sunday 23rd April. There is the chance of some light and showery rain near the North Sea, but inland areas such as London are forecast to be dry and bright. 

GEFS12z rain forecast for London Marathon


The chart below shows the maximum forecast temperatures at the same time. Earlier in the morning temperatures could be significantly lower.


GEFS12z temperature forecast for London Marathon


The forecast for the London Marathon favours dry, bright and quite chilly weather. In the sunshine it should feel quite pleasant but the early morning is expected to be distinctly nippy.

Note: Forecast confidence is higher than usual at this range. A high pressure dominated set-up has been shown quite consistently by recent computer model runs.  

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