According to Lao Dong on December 4, although the weather was sunny, many areas in Ho Chi Minh City were still covered in a layer of fog. This was the third consecutive day of fog in Ho Chi Minh City, however the fog only appeared in the morning and was not as dense as in previous days.
"This phenomenon has appeared in Ho Chi Minh City for the past few days. In the morning, riding a motorbike also feels cool. However, the air is quite uncomfortable" - Mr. Nguyen Bach Tung (Thu Duc City) shared.
Mr. Le Dinh Quyet - Head of Forecasting Department, Southern Hydrometeorological Station said that the reason for the prolonged fog phenomenon is due to cold air in the North diffusing deep to the South, causing the air temperature to decrease. The rain showers, high humidity, and light winds cause the fog to dissipate slowly.
In addition, a low pressure trough is forming over the southern sea. This low pressure trough has areas of moisture convergence, creating quite high humidity in the air. In the early morning, most of the southern provinces have humidity above 80%.
"The fog that lasted for a long time like yesterday is a normal phenomenon, not a dangerous type of weather. This fog will continue for a few more days, then it will end," Mr. Quyet said.
In Ho Chi Minh City, due to the many high-rise buildings reducing the ability of air circulation, the fog dissipates more slowly. Another reason is that there are many other dust-generating activities in the city, creating conditions for more fog to form.
On the air monitoring application Air Visual (belonging to IQAir, which owns a huge amount of aggregated data on air quality, headquartered in Switzerland) at 9:30 a.m., it shows that many areas in Ho Chi Minh City have unhealthy air quality measurement points - 152.
The concentration of fine dust PM2.5 in Ho Chi Minh City is 58µg/m³, 11.6 times higher than the value according to WHO's annual air quality guidelines.
It is forecasted that in January and February 2025, there will still be some days with similar fog in Ho Chi Minh City and the Southern provinces.
