Heavy rain has flooded the railway between Cardiff Central and Bridgend, blocking the line towards Swansea.
Additionally, flooding means all lines between Llantwit Major and Bridgend are closed.
Trains may be cancelled, revised or delayed by up to 45 minutes.
Disruption is expected until 14:00.
Customer advice:
Great Western Railway
Services between London Paddington and Swansea / Carmarthen may be revised to terminate and start back at Cardiff Central.
You can use your ticket on Transport for Wales services between Cardiff Central and Carmarthen via Swansea in both directions.
Transport for Wales
Trains are unable to run between Rhoose Cardiff International Airport and Bridgend. Services will be revised to terminate at and start back from Rhoose Cardiff International Airport.
Check before you travel:
You can check your journey using the National Rail Enquiries real-time Journey Planner.
âââââââCompensation:
You may be entitled to compensation if you experience a delay in completing your journey today. Please keep your train ticket and make a note of your journey, as both will be required to support any claim.