Distinguishing between severe cold, severe cold, humid cold, and dry cold: Which type of cold is the 'scariest'?

Surely we have heard the phrases "very cold, very cold" as above in weather reports, but have you ever wondered what the difference is between these two concepts? If so, let's find out more about this issue through the article below.

In fact, distinguishing between these two concepts is very simple, their most basic difference is the average daily temperature, specifically:

  1. Cold weather is when the average daily temperature in the area ranges from 20 to 22 degrees Celsius.
  2. Cold weather : When the average daily temperature in the area fluctuates commonly between 15 and 20 degrees Celsius.
  3. Cold spells are when the average daily temperature in the area ranges from 13 to 15 degrees Celsius.
  4. Harmful cold is when the average daily temperature in the area drops below 13 degrees Celsius (There are two types of harmful cold which we will consider in detail at the end of this article).

These are two phenomena mainly used for the plains and midlands of the North and North Central regions and these terms do not apply to the mountainous regions (the reason is that in the mountainous regions, the occurrence of these two phenomena almost happens throughout the month instead of in waves).

For example, in Sapa (Lao Cai), severe cold occurs almost throughout December, January and February.

So why do we have to distinguish between "severe cold" and "harmful cold" like that?

The reason these two concepts are so clearly separated is because in the North of our country, rice production is the main food crop and this is where agricultural production activities are most active in the cold season.

Therefore, the two concepts of "severe cold" and "damaging cold" are mainly used in the agricultural production sector to help farmers have appropriate measures to cope with this extreme weather phenomenon as well as to be aware of the level of their impact on the crop.

Scientists have researched and calculated the influence of average daily temperature on the photosynthetic ability of plants, and based on that, divided it into two levels as above.

If the cold weather only lasts for 1 day, the plant's ability to photosynthesize and grow is still normal. However, if it lasts for 2 days or more, the plant can lose its resistance and die because it is no longer able to photosynthesize and protect itself.

Another thing to note is that "severe cold" and "severe cold" must be accompanied by cloudy, overcast weather and possibly light rain (otherwise it will not be considered severe cold or severe cold even if the average daily temperature drops to 15 or 13 degrees Celsius.

Picture 1 of Distinguishing between severe cold, severe cold, humid cold, and dry cold: Which type of cold is the 'scariest'?
Classification of common cold types. (Photo: Thanh Luan).

In addition, according to Mr. Le Thanh Hai, former Director of the National Center for Hydro-Meteorological Forecasting on Science and Life , cold spells are also divided into two very typical types: Dry cold spells and wet cold spells.

  1. In which, damp cold (wet) is the type of cold that numbs the limbs with very high humidity (80 to 90%), temperature around 10 degrees Celsius with rain or even snowfall, snow cover or ice in high mountains, the temperature inside or outside is not much different.
  2. Dry cold is even more uncomfortable with air temperature can drop to 7 - 9 degrees Celsius, humidity 20 - 30%, but no rain or even sunny during the day. At night, in the mountains there is frost, frost, the temperature inside the house is a little warmer than outside.

Another common rule is that if the first half of the season is cold, severe cold or dry cold, then in the second half of the season, wet cold will occur. Thus, among the common types of cold, dry cold is the most 'fearsome' because the temperature at this time drops very low (7 to 9 degrees Celsius).