The Ping River is slightly subsiding, but the situation in Chiang Mai city remains critical as floodwaters have caused damage to economic areas.
The water level at Naowarat Bridge in the city was 4.80 metres deep at 10am on Thursday, down from 4.93m at 2am, which broke the previous record of 4.90m set 13 years ago.
The municipality warned that the crisis was not over.
The overflow of the river has wreaked havoc in downtown Chiang Mai, including the Night Bazaar, with water levels in some locations reaching as deep as one metre.
An official said floodwaters were moving towards Chiang Mai railway station and Highway 11, known as the Super Highway, which is the main road linking the city with Lampang.
The official said that residents on the other side of the road would be safe, as floodwaters cannot flow across the road.
Authorities have advised people living near the railway station to move belongings and vehicles to safe locations since Wednesday, and warned people in Lamphun to prepare for flooding within days.
Train services between Chiang Mai and Lampang are still suspended due to flooding. All trains currently stop at Lampang station, and all passengers travelling to and from Chiang Mai are being transported by bus.
