HCM City, provinces southeast of the city and some Mekong Delta provinces have experienced heavy downpours for the last three days.
Strong winds and thunder often accompanied the rains. The rainfall was relatively high, up to 45 mm in Dong Nai, Tien Giang, and Kien Giang provinces as well as Can Tho City.
Le Thi Xuan Lan, deputy head of the Southern Hydro Meteorology Forecasting Centre, said the unseasonal rains could last for a few more days, creating an unusual weather phenomenon in the last month of the year.
For the past many years, the weather at Christmas and New Year time has been dry and cool. People in the south are used to enjoying the finest weather and clearest skies of the year during the festive season.
She attributed the abnormal weather pattern to a cold front moving from the north to the south and thick clouds over the Ca Mau sea, which have triggered sporadic, downpours in many parts of the south.
The unseasonal rains have sparked worry among local flower and bonsai growers about an unsuccessful horticultural harvest this season. Apricot plants, that are bought heavily for the Tet (Lunar New Year) festival, are blooming too early.
Mrs. Lan said a cold front had also hit northern, central and south central provinces, triggering torrential rains in south central coastal areas, especially from Quang Ngai to Khanh Hoa provinces.
The rainfall is expected to measure from 40 to 70 mm in the next few days. The river water level in these provinces is likely to rise to the third warning level, the dangerous level for flooding.
Despite unseasonal rains in the last month of this year, the threat of severe prolonged spell of drought may still be on the horizon for the early months of 2009.