For areas not affected by storms, hot to very hot weather is forecast due to the influence of the high-pressure system from China that extends to cover upper Thailand and the South China Sea, the department said.
Meanwhile, thunderstorms, gusty wind, hail, and lightning strikes are expected in the Northeast before spreading to the rest of the region. People in affected areas should avoid going outdoors and keep clear of big trees and unsecured billboards. Farmers should prevent their crops from damage, the department advised.
The affected areas are as follows:
Tuesday
North: Nan, Phrae, Uttaradit, Sukhothai, Kamphaeng Phet, Phichit, Phitsanulok, Phetchabun and Tak.
Northeast: Loei, Nong Bua Lamphu, Udon Thani, Nong Khai, Bueng Kan, Sakon Nakhon, Nakhon Phanom, Mukdahan, Yasothon, Kalasin, Khon Kaen, Chaiyaphum, Nakhon Ratchasima, Maha Sarakham, Roi Et, Amnat Charoen, Buriram, Surin, Sisaket and Ubon Ratchathani.
Central: Nakhon Sawan, Uthai Thani, Chainat, Lopburi, Saraburi, Singburi, Ang Thong, Phra Nakhon Si Ayutthaya, Suphanburi, Kanchanaburi, Nakhon Pathom, Samut Sakhon, Samut Songkhram and Bangkok metropolitan area.
East: Nakhon Nayok, Prachinburi, Sa Kaeo, Chachoengsao, Chonburi, Rayong, Chanthaburi and Trat.
Wednesday
North: Chiang Mai, Lamphun, Lampang, Uttaradit, Sukhothai, Phitsanulok, Phichit, Phetchabun, Kamphaeng Phet and Tak.
Northeast: Loei and Chaiyaphum.
Central: Nakhon Sawan, Uthai Thani, Chainat, Lopburi, Saraburi, Singburi, Ang Thong, Phra Nakhon Si Ayutthaya, Suphanburi, Kanchanaburi, Ratchaburi, Nakhon Pathom, Samut Sakhon, Samut Songkhram, and Bangkok metropolitan area.
East: Nakhon Nayok, Chachoengsao, Chonburi and Rayong.
Thursday
North: Mae Hong Son, Chiang Mai, Chiang Rai, Lamphun, Lampang, Phayao, Nan, Phrae and Tak.