Irish Rail says it has moved forward its plans to wrap up DART services.
They've been suspended between Pearse and Bray due to a tidal surge which has caused major flooding on the line.
Services between Pearse and Howth / Malahide will be wound down from noon until 2pm.
Trains won't be back on track until at least tomorrow afternoon.
Spokesperson Barry Kenny says "our priority is to try and resume services as quickly as we can but it has to be safe. Our crews will be looking at whether points ways are clear and that our staff can get in."
Final trains in Dublin:
- Northern Commuter: 13:15hrs Dublin Pearse to Drogheda, 12:30hrs Drogheda to Dublin Pearse
- Maynooth Commuter: 12:48hrs Dublin Pearse to Maynooth, 13:40hrs Maynooth to Dublin Pearse
- DART: 12:25hrs Bray to Howth, 12:30hrs Greystones to Malahide, 12:32hrs Malahide to Greystones, 12:45hrs Howth to Bray - Services currently suspended between Bray & Pearse.