According to the Vietnam Meteorological and Hydrological Administration (VMHA), 10-12 storms could form in Vietnam's East Sea this year, with around half expected to hit mainland Vietnam.

"The number of storms is lower than last year and the average of previous years, but under the impact of La Nina, which will stay until autumn, heavy rainfalls could occur and lead to extreme flooding," Tran Hong Thai, head of the VMHA, told a meeting on preventing natural disasters on Monday.

The administration forecast that the rainy season would come earlier this year for northern, southern and Central Highlands regions.

In the central region, home to popular tourist cities like Da Nang, Hue and Hoi An, the amount of rainfall in October and November is expected to be higher than the average levels of previous years, causing flooding for the area.

Between March 30 and April 2, the central region had recorded abnormal heavy rains, with a rainfall volume ranging from 200 mm to 600 mm. In some places of Thua Thien Hue Province, the volume rose to over 800 mm.

Floods triggered by rains killed four people in the region and caused an economic loss of VND2.3 trillion ($100.85 million).