The Southern Meteorological Centre warned that from 11 to 13 September a broad band of intense rain will sweep Ho Chi Minh City (HCMC) and the surrounding provinces. A tropical convergence zone reinforced by a strong southwest monsoon is expected to produce daily totals of 60‑140 mm across the city, with isolated peaks exceeding 150 mm in districts such as Củ Chi, Thủ Đức, Hóc Môn and in the former Bình Dương districts of Dầu Tiếng, Phú Giáo and Bàu Bàng. Rainfall forecasts for the wider south include 130‑150 mm in Bà Rịa‑Vũng Tàu, 100‑150 mm in Lâm Đồng, Đồng Nai and Tây Ninh, and 80‑140 mm in An Giang and Cà Mau.
Measurements recorded on 10 September already showed unprecedented urban totals: Củ Chi 127.2 mm, Cát Lái 126.4 mm, Thủ Đức 113 mm and Hóc Môn about 104 mm, the highest since the start of the year. Heavy rain began around 17:00 and quickly inundated low‑lying streets, with water depths of 30‑50 cm reported in the An Phú, Đỗ Xuân Hợp, Quốc Hương and Thảo Điền tunnels, as well as in markets and the former Eastern Bus Station. Vehicles stalled, traffic stalled for hours, and many households suffered water‑logged furniture and appliances.
Authorities urged residents to avoid peak‑hour travel, secure loose objects, and prepare for possible hail, lightning and gusty winds. Tidal forecasts indicate the Saigon River will reach alert level 2 on 12‑13 September, while Thu Dầu Một station may hit alert 3, and the Mekong River at Cần Thơ and Vĩnh Long could approach or exceed alert 3. The rain is expected to taper after 14 September, returning to moderate levels of 20‑40 mm.