The Southern Regional Hydro-Meteorological Center forecasts widespread downpours across the region lasting through Sept. 21. Total rainfall will generally range from 100 to 250 millimeters, with some areas receiving higher amounts.

Floodwaters nearly reach motorcycle seats on Quoc Huong Street in the Thao Dien area in eastern HCMC following heavy rains on the evening of Sept. 10, 2026. Photo by VnExpress/Thanh Tung

The severe weather stems from a strengthening northern cold air mass moving south. This system will push a low-pressure trough from the north-central region into southern Vietnam.

This trough will intensify the southwest monsoon and trigger widespread downpours.

The center announced on Tuesday that Ho Chi Minh City will receive between 100 and 200 millimeters of rain, with certain areas exceeding those totals.

Authorities warned residents to remain alert for flooding in low-lying areas and along waterways. The incoming thunderstorms also carry the risk of tornadoes, lightning, hail, and strong gusts.

Weather conditions will shift in the latter half of the month as the subtropical high strengthens and the southwest monsoon weakens.

This change will bring decreased rainfall and more frequent hot weather. Localized heatwaves could push maximum temperatures to 35-36 C on certain days.