According to the National Centre for Hydro-Meteorological Forecasting, rainfall across the country is anticipated to decrease rapidly after May 21. Hot weather will first return to Central Vietnam on May 22 before expanding to northern provinces between May 23 and 28.

Meteorologists said this could become one of the strongest early summer heatwaves of 2026 as temperatures are forecast to rise sharply in many locations. Northern and central regions are set to face severe and prolonged heat, with daytime highs surpassing 40°C in some areas. Actual outdoor temperatures may feel even hotter due to low humidity and heat retained by concrete and urban infrastructure.

Weather experts explained that the heatwave is being driven by strengthening subtropical high-pressure systems over the East Sea. The system is gradually shifting northward, directly affecting weather conditions across the northern and central regions of Vietnam.

At the same time, a western low-pressure hot zone is forecast to develop and expand eastward from May 23, further intensifying heat conditions across large parts of the country.

Central Vietnam is set to be the region most heavily impacted by the upcoming heatwave, with prolonged sunshine, dry conditions, and limited rainfall forecast over the coming days.

In Southern Vietnam and Ho Chi Minh City, southwest monsoon winds are currently weak, causing rainfall to decrease while temperatures rise again. From May 22, daytime temperatures in Ho Chi Minh City will range between 33 and 34°C. Localised heatwaves could develop in some districts from May 23, with temperatures climbing to 35°C.

Despite the return of hot weather, meteorologists believe the heatwave in southern Vietnam may not last long. Around May 27 and May 28, a low-pressure trough could form over the central and southern East Sea, creating favorable conditions for widespread heavy rain to return across Ho Chi Minh City and southern provinces.

Meteorological experts also warned that the current seasonal transition period is producing alternating patterns of intense heat and strong thunderstorms, resulting in large temperature fluctuations between day and night. These conditions increase the risk of extreme weather events including lightning, hailstorms, tornadoes, and strong wind gusts.

Such severe weather could damage crops, uproot trees, disrupt transportation infrastructure, and affect residential areas in vulnerable regions.

People are advised to avoid prolonged outdoor activities during peak heat hours between 11 a.m. and 4 p.m., stay hydrated, and seek safe shelter immediately when thunderstorms develop.

Weak cold air brings rain, Northern Vietnam cools after heatwave

VOV.VN - After several days of intense heat, weather conditions across many parts of Vietnam, especially in the north, shifted noticeably as widespread showers and thunderstorms arrived from the evening of May 16.