More floods are expected in Chiang Mai on Friday, with water levels along the Ping River expected to reach 4.95 metres starting in the morning.
Recent heavy downpours in upstream areas have caused the Ping River to rise rapidly, governor Nirat Pongsitthithaworn said on Thursday.
He advised residents living along the river to move their vehicles and other valuables to higher ground.
All agencies have been told to provide help to people who need it and to reinforce flood-prone areas with barriers and sandbags.
A flash flood was reported in Mae Rim district of the northern province at 3am on Thursday following heavy rain.
The depth of the Ping River at the Nawarat Bridge in Muang district reached the critical level of 4.20 metres at 4pm on Thursday.
The river was expected to peak at 4.95 metres at 2am Friday morning.
In Chiang Rai, the Mae Sai River overflowed near the first Thai-Myanmar Friendship Bridge in Mae Sai district at 9am on Thursday following a downpour that began on Wednesday.
Downpours in the northern, northeastern, central and eastern regions were expected to start easing on Friday.
However, the western part of the North should expect more heavy downpours until Oct 12.