The department warned residents in the upper part of the country to expect severe weather conditions and advised them to keep away from large trees and unsecured billboards. Farmers should take measures to prevent damage to crops and livestock.
It also warned that accumulated rain may cause flash flooding and overflows, especially along waterways near foothills and lowlands, and advised caution on the roads.
In the South, a southeasterly wind over the Andaman Sea, the South and the Gulf, will bring isolated heavy rains. Shipping should proceed with caution and keep away from storms, the department said.
The weather forecast for the next 24 hours is as follows:
Bangkok Metropolitan Area
Scattered thundershowers in 60% of the area. Temperature lows of 25-26 °C and highs of 30-35 °C.
North
Hot to very hot day with scattered thundershowers, gusty winds and isolated heavy rains in Mae Hong Son, Chiang Mai, Chiang Rai, Lamphun, Lampang, Phayao, Nan, Phrae, Uttaradit, Tak, Phichit, Phitsanulok and Phetchabun. Lows of 23-27 °C and highs of 35-40 °C.
Northeast
Hot day with scattered thundershowers in Loei, Nong Khai, Bueng Kan, Nong Bua Lamphu, Udon Thani, Sakon Nakhon, Chaiyaphum, Khon Kaen, Nakhon Ratchasima, Buriram and Surin. Lows of 24-26 °C and highs of 34-37 °C.
Central
Hot day with scattered thundershowers, gusty winds and isolated heavy rains in Nakhon Sawan, Uthai Thani, Chainat, Lopburi, Saraburi, Singburi, Ang Thong, Phra Nakhon Si Ayutthaya, Suphan Buri, Kanchanaburi and Ratchaburi. Lows of 24-26 °C and highs of 35-40 °C.
East
Scattered thundershowers and isolated heavy rains in Nakhon Nayok, Chachoengsao, Chonburi, Rayong, Chanthaburi and Trat. Lows of 24-26 °C and highs of 31-36 °C. Waves below 1 metre high and above a metre in thundershowers.
South (East Coast)
Hot day with scattered thundershowers and isolated heavy rains in Phetchaburi, Prachuap Khiri Khan, Chumphon, Surat Thani, Nakhon Si Thammarat, Phatthalung and Songkhla. Lows of 25-26 °C and highs of 33-37 °C. Wave height below 1 metre, higher in thundershowers.
South (West Coast)
Scattered thundershowers and isolated heavy rains in Ranong, Phang Nga, Phuket, Krabi, Trang and Satun. Lows of 25-27 °C and highs of 33-36 °C. Wave height below 1 metre, higher in thundershowers.