Interior Minister Anupong Paojinda said people should not fear major flooding in Bangkok and other provinces.
He said the situation remains under control as the country's key reservoirs are not yet full.
"Although one or two tropical storms are expected later this year, these dams are still well below their retention capacity," Gen Anupong said in parliament on Monday.
This year's total precipitation is expected to reach 1,500 millimetres, about 26% higher than average annual rainfall.
Gen Anupong noted that in previous years floods were brought on by tropical storms, but this year the increased rainfall is the result of a wetter monsoon.
"Authorities continue to stick with the usual water management plan, which is designed to control floods, while at the same time keep sufficient water in dams and reservoirs for the dry season," he said.
Currently, floods have been reported in 13 provinces: Phayao, Nan, Chiang Mai, Lamphun, Lampang, Phetchabun, Kalasin, Khon Kaen, Nong Bua Lam Phu, Pathum Thani, Samut Prakan, Rayong and Chanthaburi.
Gen Anupong said authorities in Bangkok have adopted a special water management system that diverts water run-off from the provinces away from the capital, allowing authorities to focus on draining excess rainwater from the city's streets.
"In short, the overall situation is under control," he said.
Separately, Bangkok governor Chadchart Sittipunt said the situation in Bangkok was improving.
Water levels in most of the city's major canals were decreasing – except along Klong Prawet Buri Rom in eastern Bangkok, which rose by 60 centimetres on Monday, worsening floods in communities along the canal.
