The changes are due to engineering work or seasonal changes.
These will affect trains from Saturday to Bank Holiday Monday (May 24 to May 26).
We have outlined and simplified the details so you can plan your journey this weekend.
Saturday (May 24):
No Southern trains will run between Shepherds Bush and Watford Junction.
Sunday and Monday (May 25 and May 26):
No Southern trains will run between Clapham Junction and Watford Junction.
Passengers should use Southern trains between Clapham Junction and London Victoria.
On Saturday only, passengers can use alternative London Overground (Mildmay line) trains between Clapham Junction and Willesden Junction.
Sunday only (May 25):
Until 9am, trains to and from London Bridge will run to an amended timetable with some replacement buses.
Replacement buses will run between New Cross Gate and Crystal Palace.
Trains between London Bridge and Caterham will run to an amended timetable and will be diverted, with extended journey times.
Trains which usually run between London Victoria and London Bridge will be amended to only run between London Victoria and Crystal Palace.
Monday only (May 26):
Engineering work is taking place between Purley and Caterham and Tattenham Corner, closing all lines overnight on Monday evening.
After approximately 11.45pm each night, replacement buses will run between East Croydon, Purley and Caterham, and Tattenham Corner.
