Immerse yourself in the heart of Central London at the London 100, an ultramarathon that showcases the city’s diverse landscapes and hidden gems. This iconic race offers three challenge distances: 100km, 50km, and a more accessible 25km option for runners looking to step up from marathons or half-marathons. Starting at a state-of-the-art indoor Run HQ in Central London, participants embark on four distinct 25km routes that venture north, south, east, and west of the city. Each route reveals unique terrains and scenic vistas, allowing you to explore areas of London that are often overlooked by tourists. Discover hidden trails, secret parks, and lesser-known neighborhoods while also passing iconic landmarks such as Big Ben, Buckingham Palace, and Tower Bridge. The event is designed for experienced ultramarathoners who thrive on long-distance challenges, as well as runners looking to push their limits in a supportive environment. Whether you’re chasing personal records or simply enjoying the camaraderie of fellow athletes, London 100 offers an unforgettable journey through one of the world’s most vibrant cities. Experience the thrill and beauty of running across different parts of London, from bustling streets to serene green spaces, making this ultramarathon a must for any serious runner.
Races Offered
London 25
May 09, 2026
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Distance —
25K
terrain
Type —
Running
timer
09:00
London 100
Jun 12, 2027
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Distance —
100K
terrain
Type —
Running
timer
07:00
sell
£128.56
London 50
Jun 12, 2027
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Distance —
50K
terrain
Type —
Running
timer
09:00
sell
£89.13
London 25km (East)
Jun 12, 2027
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Distance —
25K
terrain
Type —
Running
timer
249 days remaining
sell
£59.14
Weather History
These values represent the 3-year monthly averages for June in London.
thermostatTemperature
9.4° / 18.5°
wb_sunnyFeels like
6.9° / 15.5°
light_mode
Avg sunshine hours
10h 29m
water_drop
Avg rainfall
1.5 mm
ac_unit
Avg snowfall
—
air
Avg wind speed
12.5 km/h (Gentle breeze)
opacity
Sweat loss rate
Low
terrain
Course conditions
Firm and slightly soft
sunny
Max UV Index
Moderate (4.2)
humidity_mid
Humidity
72.0%
wb_twilight
Sunrise
05:07
nightlight
Sunset
20:46
About London
Learn more about the host city, London.
The City of Westminster is a London borough with city status in Greater London, England. It is the site of the United Kingdom's Houses of Parliament and much of the British government. It contains a large part of central London, including most of the West End, such as the major shopping areas around Oxford Street, Regent Street, Piccadilly and Bond Street, and the entertainment district of Soho. Many London landmarks are within the borough, including Buckingham Palace, Westminster Abbey, Whitehall, Westminster Cathedral, 10 Downing Street, and Trafalgar Square.
