Meanwhile, HCM City and southern provinces face several days of heavy rain and thunderstorms.

Northern Vietnam still sees 34-degree heat in mid-October

According to the Southern Regional Hydrometeorological Center, the main weather pattern during October 17-27, 2026, will involve weakening cold air, with a possible weak eastward-shifting surge around October 20-21.

Meanwhile, disturbances in upper-level easterly winds are expected to intensify, increasing rainfall across southern Vietnam.

The National Center for Hydro-Meteorological Forecasting (NCHMF) said cold air outbreaks have remained infrequent and weak despite the arrival of mid-October.

As a result, northern Vietnam is expected to continue experiencing sunny conditions, with daytime highs reaching 33-34 degrees Celsius in many areas.

Around October 20-22, a weak cold front may move into Vietnam from an easterly direction, lowering temperatures in the North by only about one degree Celsius, insufficient to bring genuinely cool weather.

In Hanoi, sunny conditions and relatively hot afternoons are expected over the coming days and during October 23-27.

Daytime temperatures could reach 33-34 degrees Celsius, while nighttime temperatures are forecast to range between 24 and 26 degrees Celsius.

On October 18-19, northern Vietnam and areas from Thanh Hoa to Hue City are expected to experience isolated nighttime showers, with light early-morning fog in some places and sunshine during the day.

Similar conditions are forecast to continue from the night of October 19 through October 27.

However, northeastern Vietnam and the area from Thanh Hoa to Hue City could experience scattered showers and thunderstorms on October 21-22, with locally heavy rainfall.

HCM City and southern Vietnam warned of heavy rain and thunderstorms

In contrast to the unusually warm autumn weather in northern Vietnam, rainfall is expected to increase across the South in the coming days.

According to the Southern Regional Hydrometeorological Center, strengthening upper-level easterly wind disturbances, combined with weather systems moving inland from the sea, will create increasingly unstable atmospheric conditions.

Widespread rainfall is expected across southern Vietnam, including HCM City, with moderate to heavy rain and potentially very heavy downpours in some locations.

Meteorological authorities warned that thunderstorms during this period could be accompanied by lightning, hail and strong wind gusts.

In HCM City, heavy late-afternoon and evening rainfall could increase the risk of localized flooding and disrupt travel during peak commuting hours.

Meanwhile, the NCHMF forecast isolated showers and thunderstorms along the south-central coast.

Northern parts of the region could experience scattered rainfall on October 21-22, while southern areas may see rain from the night of October 19 through October 20, with locally heavy downpours.

The Central Highlands and southern Vietnam are also expected to experience occasional showers and thunderstorms, interspersed with sunny daytime conditions.

In southern Vietnam and Lam Dong Province, scattered evening showers and thunderstorms are forecast through approximately October 21-22, with locally heavy rainfall.

Scattered thunderstorms are expected to continue afterward.

Residents have been advised to remain alert for tornadoes, lightning, hail and strong wind gusts during thunderstorms, while taking precautions against flooding in low-lying areas.

Meteorological authorities also said El Nino is forecast to become particularly strong during the final months of 2026.

During October and November, average temperatures nationwide are expected to exceed the long-term average by 1-2 degrees Celsius, with even greater anomalies in some areas.

In December, temperatures are forecast to remain approximately 0.5-1.5 degrees Celsius above average.

In the Central Highlands and southern Vietnam, temperatures could exceed historical averages by 1.5-2.5 degrees Celsius.

The influence of El Nino is also expected to weaken cold air outbreaks compared with typical seasonal conditions.

Severe and prolonged cold spells may arrive later than usual, while the number of days experiencing such conditions could be lower than the long-term average for the same period.

However, meteorological authorities cautioned that localized episodes of intense cold weather cannot be ruled out.

Bao Anh