Over the past 4 days, northern Vietnam and the Thanh Hoa to Quang Tri area have recorded peak temperatures of 35-37 degrees Celsius. This unusual warmth, lasting from 6:00 a.m. to nearly 6:00 p.m., has made autumn in northern Vietnam feel like summer. The National Center for Hydro-Meteorological Forecasting attributed this to the southern edge of a low-pressure trough, compressed by cold air moving down from China.

Hanoi's Lang station reported temperatures exceeding 38 degrees Celsius on both 29/9 and 30/9. On 29/9, the mercury hit 38,4 degrees Celsius, surpassing the historical record of 38,2 degrees Celsius set on 8/9/2025. Hoai Duc and Ha Dong stations also recorded temperatures above 37 degrees Celsius during these two days.

Commuters in the heat in Hanoi, noon on 2/10. Photo: Hoang Giang

Other locations also registered record high temperatures for September. Mai Chau station in Phu Tho reached 37,4 degrees Celsius, matching its highest recorded temperature on 19/9/2017. Bach Long Vi station in Hai Phong recorded 34,4 degrees Celsius, exceeding its previous record of 34,3 degrees Celsius from 5/9/2020. Hung Yen station hit 37 degrees Celsius, surpassing the 36,9 degrees Celsius recorded on 29/9.

Son La and Phu Tho experienced prolonged heat, with temperatures above 37 degrees Celsius at Yen Chau and Mai Chau stations for three consecutive days from 29/9 to 1/10. Several delta areas, including Hai Duong in Hai Phong and Nho Quan in Ninh Binh, also saw temperatures above 37 degrees Celsius.

The meteorological agency noted that this heatwave in late September and early October is not an unusual phenomenon. However, temperatures between 35-38 degrees Celsius at this time create a contrasting sensation compared to typical northern autumn weather. Normally, autumn sun is not as prolonged or intense as in the peak of summer, due to reduced solar radiation, shorter daylight hours, and cooling temperatures as cold air from the north increases.

The current heatwave is showing signs of decline as a mass of cold air moves down from southern China. The meteorological agency forecasts that the cold air will affect the northern mountainous and midland regions on the night of 4/10. It will reach the northern delta early morning and day 5/10, then expand towards Northwest Northern Vietnam and the Thanh Hoa to Hue area.

This cold air mass is expected to be quite strong. From the night of 4/10, Northeast Northern Vietnam and Thanh Hoa will turn cold, with minimum temperatures generally ranging from 19-22 degrees Celsius, and high mountainous areas seeing 14-17 degrees Celsius. In Hanoi, the cold air will begin to affect the region from early morning on 5/10, bringing colder weather.

Due to the cold air, northern Vietnam will experience thunderstorms from 4/10 to the morning of 5/10. From the night of 4/10 to 6/10, the thunderstorm activity will shift south to the Thanh Hoa to Hue region. These storms may bring whirlwinds, lightning, hail, and strong gusts.

At sea, from early morning and morning on 5/10, the Gulf of Tonkin will see winds shift to the northeast, reaching level 6, occasionally level 7, with gusts of level 8-9 and waves 2-3 meters high. From 5/10, the northern East Sea will experience northeast winds of level 6-7, with gusts of level 8 and waves 2-4 meters high. From 6/10, the strong wind area will expand to the northern East Sea, including the Hoang Sa archipelago.

Gia Chinh