To welcome in the summer, cyclists will be riding through the night from Greenwich to Primrose Hill.
This year's Midsummer Madness cycle ride will see the early risers setting off from Cutty Sark Gardens in Greenwich at 2am on June 21, the morning of the summer solstice.
They then stop at Southwark Needle by London Bridge to collect more riders before setting off again to Primrose Hill, welcoming the sunrise at around 4.40am.
Previous years have seen more than 100 London cyclists foregoing their beauty sleep to take part.
It is being run by Deptford's the Dog and Bell Crew, an informal collective of social cyclists based. The ride is also being organised by the London Cycling Campaign.