According to the National Center for Hydro-Meteorological Forecasting, temperatures were significantly above long-term averages across most of Vietnam in October.
Average temperatures were 1–2°C above normal in most regions. Northern Vietnam was 2–3°C above average, while some parts of the south were 0.5–1°C higher.
The nationwide average for October was 26.30°C, 1.74°C above the long-term average for the period. It was the highest October average in the 65-year observation series dating back to 1961.
During the month, 61 weather stations recorded an absolute daily high at or above the historical value for the same period.
Another 98 stations recorded a monthly average at or above the historical record. Northern Vietnam accounted for 87 of those stations, showing how unusual the October heat was in the north.
From September 28 to October 2, northern Vietnam experienced a widespread heatwave. Maximum temperatures were generally 35–37°C and exceeded 37°C in some places.
It was the first widespread October heatwave in the region since 1991.
At Yen Chau station in Son La province, the temperature reached 38.3°C on October 3, compared with the previous record of 37.5°C.
At Muong Te station in Lai Chau province, the temperature reached 38°C on October 2, above the 37.2°C record set in 1991.
At Mu Cang Chai station in Lao Cai province, the temperature reached 34.2°C, 2.9°C above the previous record.
In Hanoi, Lang station recorded a daily high of 37.1°C on October 2, beating the previous October record by 0.7°C.
The Hoai Duc and Ha Dong stations both recorded 36.5°C.
At Hon Dau station in Hai Phong, the temperature reached 37.2°C, 2.4°C above the previous record.
The records were not limited to daily highs. Average temperatures for the entire month also rose sharply in many areas.
At Vinh Yen station in Phu Tho province, the October average reached 32.1°C, 1°C above the previous record.
In Bac Me and Dong Van in Tuyen Quang province, the October average exceeded the previous record by 1.6°C at both stations.
Why was the heat unusual?
Meteorologists said very strong El Niño activity was one factor contributing to the higher temperatures.
Cold air was also not active enough in October to keep temperatures down for a long period.
The National Center for Hydro-Meteorological Forecasting expects El Niño to remain very strong from November 2026 through January 2027, with a probability of 96%.
In November, the national average temperature is forecast to be 1–2°C above the long-term average.
Cold air is expected to be weaker than usual. Strong and prolonged cold spells in northern Vietnam and the northern central region are forecast to arrive late, with fewer cold days than average. Strong cold spells may still occur, but they are not expected to last long.
Sources: Dân Trí
