Train services to and from Chiang Mai have returned to normal after the track was damaged and blocked by a landslide near Khun Tan station in Lamphun province on Sunday evening.
The State Railway of Thailand on Sunday night declared the line safe after work crews cleared and repaired the track, and tested it.
The announcement opened the way for halted northern trains to continue their journeys to Chiang Mai, and Chiang Mai-Bangkok services to also resume.
Heavy rain in the northern province triggered a landslide that blocked the track at the entrance to Khun Tan tunnel in Lamphun at 5.18pm on Sunday.