The flood level was receding in Chiang Mai city on Monday as the flood surge flowed down the Ping River into southern parts of the province and neighbouring Lamphun.
The Ping was 3.45 metres deep at the Naowarat Bridge monitoring station at 10am on Monday, according to the Chiang Mai Municipality website. The river had remained stable at that depth for six hours, well below the critical point of 4.20m, it said.
Work gangs continued to help drain the water from still-flooded areas in the city, cleaning away the debris left behind and assisting residents.
Kuakul Manasamphansakul, director of the Chiang Mai irrigation office, said attention had shifted to the situation in flooded downstream Saraphi, a southern district bordering Lamphun, which was still receiving water released from Chiang Mai. It was also raining there.
Mr Kuakul said they were worried that forecast further rain would only add to the problem in Chiang Mai and Lamphun.
The Public Relations Office in Lamphun said the Kuang River in Muang district had overflowed on Monday morning. The Kuang passes through Muang district before merging into the Ping.
The Meteorological Department forecast was for turbulence, gusty winds and heavy rain in the northern and northeastern regions, with temperatures expected to be slightly lower, with a moderate high pressure zone extending from China over the upper part of Thailand until Friday.
Chiang Mai is one of 17 inundated provinces in the country, the Office of the National Water Resources reported. The agency retained Chiang Mai on its flood alert list until Wednesday due to rain and overflowing rivers.
The State Railway of Thailand said all northern train services had returned to normal since Saturday. It was still watching locations at risk of flooding again.