Chiang Mai and Loei provinces were hit by storm Sinlaku as it moved into Thailand, with heavy rain and flash-floods expected until at least Tuesday.
The Kuang River overflowed and flooded San Sai district of Chiang Mai overnight. Residents escaped flash floods by moving to high ground.
Officials denied reports that the sudden flood was caused by a leak at Mae Kuang Dam in Doi Saket district. The flooding was due to damage to a small check-dam in San Sai, built to slow the river's flow, officials said.
In Loei, torrential rain flooded communities in at least three districts on Sunday morning, but the water was receding on Monday as the level of the Loei River dropped.
Loei was the province most damaged by flooding on Sunday, with about 700 households affected.
Three northeastern and six northern provinces, including Chiang Mai and Loei, bore the brunt of the storm.
The Meteorological Department issued another weather alert, but said Sinlaku was weakening as it entered Nan on Monday morning. Heavy rain was expected in at least 44 provinces, most of them in the northern and northeastern regions, until Tuesday.
