The westerly trough covers the upper North and Northeast while southerly and the southeasterly winds bring humidity from the South China Sea to the Northeast, the East, the Central and the lower North regions. Summer storms with gusty winds, hail and lightning are also forecast for some areas of upper Thailand.
The department has urged people to keep off unsecured buildings and outdoor installations. Farmers have been warned of damage to crops.
Meanwhile, the dust situation in Bangkok will ease due to strong southerly and southwesterly winds blowing across the city and its vicinity. However, the smog situation in the upper North could worsen in the morning due to bad ascending of air-parcel.
Forecast for Bangkok metropolis and its vicinity: Minimum temperature 26-27 °C; maximum temperature 35-38°C. Southerly winds blowing at 10-20 km/hr.