Why is it cold when the forecast is cold but it doesn't feel cold?

Because this cold air mass is very dry, the sky is less cloudy and sunny, so the lowest temperature usually falls at night and early morning, and it is less cold during the day.

Ms. Nguyen Thi Thanh Binh, a forecaster at the National Center for Hydro-Meteorological Forecasting, said this when reporting on the cold air mass affecting the North on the morning of November 21.

According to Ms. Binh, due to the influence of cold air, in most of the Northern Delta, the lowest temperature at night and early morning is around 20-22 degrees Celsius, in mountainous areas it drops below 17 degrees Celsius.

Because it is still sunny, the daytime temperature does decrease but not much, we hardly feel it. (Illustration: internet).

At the Trung Khanh meteorological station (Cao Bang), the lowest temperature on the night of November 18 and early morning of November 19 was 18.8 degrees Celsius. Last night and early this morning, it dropped to 16.6 degrees Celsius.

Similarly, in the capital Hanoi, the Ha Dong meteorological station recorded the lowest temperature dropping to 21.5 degrees Celsius in the early morning of November 20.

"Please note that when the forecast bulletin is released, it states that the lowest temperature will decrease and remain at 20-22 degrees Celsius, in mountainous areas below 17 degrees Celsius. The wind in the Gulf of Tonkin is strong at level 6, level 7, gusting to level 8. During the day, there are few clouds and sunny weather, so we feel that the weather will change little.

"Because this cold air mass is very dry, the sky is still partly cloudy and sunny. In fact, the lowest temperatures often fall at night and early morning. Based on measurements from the meteorological station network in the north, the lowest temperatures are also decreasing," said Ms. Binh.

According to Ms. Binh, because it is still sunny during the day, the temperature during the day decreases but not much, we hardly feel it. At night, the temperature decreases, causing the temperature range between day and night to increase, which can easily affect our health such as respiratory problems.

One of the factors to note when cold air flows in is that the northeast wind in the Gulf of Tonkin will strengthen, causing rough seas, affecting ships and activities at sea. Fishermen and activities at sea need to pay attention when going out to sea, minimizing the impact.

The National Center for Hydro-Meteorological Forecasting predicts that from tonight to the night of November 22, from Quang Tri to Quang Ngai, there will be rain from 40-100mm, locally over 200mm in some places.

In addition, today and tonight, in the area from Ha Tinh to Quang Binh and Binh Dinh, there will be rain, showers, locally heavy rain with rainfall from 20-40mm, locally over 60mm.

From November 23 to 24, in the area from Quang Tri to Binh Dinh, there will continue to be moderate rain, heavy rain, locally very heavy rain and thunderstorms with rainfall from 40-100mm, locally over 200mm.

Thunderstorms may cause tornadoes, lightning and strong gusts of wind.