TMD warns of storms, hail and fierce heat across upper Thailand

Thai Meteorological Department (TMD) forecast for April 19-24, 2026.

During April 19-20, 2026, upper Thailand will experience summer storms, with thunderstorms, gusty winds and isolated hail, including possible lightning in some areas.

This is because a high-pressure system or cold air mass from China will extend over the South China Sea, causing the southerly and southeasterly winds prevailing over upper Thailand to strengthen, while upper Thailand remains hot to very hot.

During April 21-22, 2026, rain will decrease in upper Thailand, although isolated thunderstorms will remain, with hot weather during the day.

This is because the southerly and southeasterly winds prevailing over the Northeast and the East will weaken.

After that, during April 23-24, 2026, upper Thailand will again experience summer storms, with thunderstorms, gusty winds and isolated hail, including lightning.

This is because another high-pressure system or cold air mass from China will extend over the South China Sea and the Northeast, while upper Thailand remains hot to very hot.

In the South, during April 19-22, 2026, thunderstorms will increase as the southeasterly winds prevailing over the Gulf of Thailand and the South strengthen.

During April 23-24, 2026, rain will decrease in the South as the southeasterly winds prevailing over the Gulf of Thailand and the South weaken.

Waves in the Gulf of Thailand and the Andaman Sea will be about 1 metre high, and above 2 metres high in thundershowers.

Caution

People across Thailand are advised to take care of their health due to the hot to very hot weather by avoiding work or activities in open areas for long periods.

Mariners in both the Gulf of Thailand and the Andaman Sea should avoid sailing in areas with thundershowers throughout April 19-20 and 23-24, 2026.

People in upper Thailand are urged to beware of summer storms by avoiding open areas, large trees, buildings and unsecured billboards.

Farmers should strengthen fruit trees and prepare to prevent possible damage to agricultural produce and livestock, while also taking care of their health during changing weather conditions.

The Thai Meteorological Department regional forecast for April 19-24, 2026

Northern

April 19-20

• Generally hot to very hot, with thunderstorms in 10-30% of the area, gusty winds and isolated hail, mostly in the eastern part of the region.

April 21-22

• Generally hot to very hot, with haze during the day and isolated thunderstorms with gusty winds. Southwesterly winds 5-15 km/h.

April 23-24, 2026

• Generally hot, and very hot in some areas, with haze during the day and thunderstorms in 10-20% of the area, gusty winds and isolated hail. Southeasterly winds 5-15 km/h.
• Minimum temperature 20-28°C. Maximum temperature 36-43°C.

Northeastern

April 19-20, 2026

• Hot to very hot, with thunderstorms in 20-40% of the area, gusty winds and isolated hail. Southerly winds 10-20 km/h. Minimum temperature 22-27°C. Maximum temperature 36-42°C.

April 21-22, 2026

• Generally hot, with isolated thunderstorms and gusty winds. Southerly winds 10-15 km/h.

April 23-24, 2026

• Generally hot, with thunderstorms in 30-40% of the area, gusty winds and isolated hail. Southeasterly winds 10-20 km/h.
• Minimum temperature 21-26°C. Maximum temperature 35-39°C.

Central

April 19-20, 2026

• Generally hot, and very hot in some areas, with haze during the day and thunderstorms in 10-30% of the area, with gusty winds in some places, mostly in the eastern part of the region. Southerly winds 10-20 km/h.

April 21-23, 2026

• Generally hot, and very hot in some areas, with isolated thunderstorms, mostly in the lower part of the region. Southerly winds 10-15 km/h.

April 24, 2026

• Generally hot, and very hot in some areas, with thunderstorms in 10-30% of the area, gusty winds and isolated hail. Southeasterly winds 10-20 km/h.
• Minimum temperature 23-28°C. Maximum temperature 36-42°C.

Eastern

April 19-20, 2026

• Generally hot, and very hot in some areas, with thunderstorms in 20-40% of the area, gusty winds and isolated hail. Southerly winds 15-30 km/h. Waves around 1 metre high, and above 2 metres high in thundershowers.

April 21-23, 2026

• Thunderstorms in 10-20% of the area. Southerly winds 10-30 km/h. Waves below 1 metre high, and above 1 metre high in thundershowers.

April 24, 2026

• Generally hot, with thunderstorms in 40-60% of the area and gusty winds. Southeasterly winds 10-30 km/h. Waves below 1 metre high, and above 1 metre high in thundershowers.
• Minimum temperature 23-29°C. Maximum temperature 32-40°C.

Southern (East Coast)

April 19-22, 2026

• Hot during the day, with thunderstorms in 20-40% of the area. Southeasterly winds 15-30 km/h. Sea waves around 1 metre high, and above 2 metres high in thundershowers.

April 23-24, 2026

• Hot during the day, with thunderstorms in 10-20% of the area. Southeasterly winds 10-30 km/h. Sea waves below 1 metre high, and above 1 metre high in thundershowers.
• Minimum temperature 23-27°C. Maximum temperature 33-38°C.

Southern (West Coast)

April 19-22, 2026

• Hot during the day, with thunderstorms in 20-40% of the area. Easterly winds 15-30 km/h. Sea waves below 1 metre high, and above 1 metre high in thundershowers.

April 23-24, 2026

• Hot during the day, with thunderstorms in 10-30% of the area. Easterly winds 10-30 km/h. Sea waves below 1 metre high, and above 1 metre high in thundershowers.
• Minimum temperature 24-28°C. Maximum temperature 33-37°C.

Bangkok Metropolis and Vicinity

April 19-20, 2026

• Generally hot, and very hot in some areas, with haze during the day and thunderstorms in 10-30% of the area, with gusty winds in some places. Southerly winds 10-20 km/h.

April 21-23, 2026

• Generally hot, with thunderstorms in 10-20% of the area. Southerly winds 10-15 km/h.

April 24, 2026

• Generally hot, and very hot in some areas, with thunderstorms in 20-40% of the area and gusty winds. Southeasterly winds 10-20 km/h.
• Minimum temperature 26-29°C. Maximum temperature 33-40°C.