People in these areas have been advised to remain indoors and stay away from large trees and unsecured billboards.
TMD is also advising people against wearing metallic items and using mobile phones during thunderstorms. Farmers have also been advised to secure their crops and livestock.
Waves in the upper Gulf of Thailand and the Andaman Sea will be 1-2 metres high and even higher during thunderstorms. Ships have been advised to proceed with caution and stay anchored during showers.
Summer storms are expected in the following provinces:
North
Mae Hong Son, Chiang Mai, Chiang Rai, Lamphun, Lampang, Phayao, Nan, Phrae, Uttaradit, Tak, Sukhothai, Kamphaeng Phet, Phichit, Phitsanulok and Phetchabun.
Northeast
Loei, Nong Khai, Bueng Kan, Sakon Nakhon, Udon Thani, Nong Bua Lamphu, Nakhon Phanom, Kalasin, Maha Sarakham, Roi Et, Chaiyaphum, Khon Kaen, Mukdahan, Yasothon, Amnat Charoen, Nakhon Ratchasima, Buri Ram, Surin, Si Sa Ket and Ubon Ratchathani.
Central
Nakhon Sawan, Uthai Thani, Chai Nat, Kanchanaburi, Ratchaburi, Suphanburi, Lopburi, Saraburi, Singburi, Ang Thong, Ayutthaya, Samut Songkhram, Samut Sakhon, Nakhon Pathom, Bangkok and adjacent provinces.
East
Nakhon Nayok, Prachinburi, Sa Kaew, Chachoengsao, Chonburi, Rayong, Chanthaburi and Trat.