Finally cool? Autumn heat: I don't exist? Please beware of this wave of "residual heat" →

The dog days are over, and it seems that there is a pleasantly cool breeze in the morning and evening. Is the task of preventing heatstroke over? No, the autumn heat wave may appear, so we still need to pay attention to prevention.

01 How did the name “ Autumn Tiger ” come about?

"Autumn" refers to autumn, and "tiger" is often used as a symbol of bravery and majesty in Chinese culture. "Autumn tiger" describes the hot weather in autumn that is as ferocious as a tiger.

In ancient times, people could only predict weather changes by observing natural phenomena and accumulating experience. For this purpose, they created many vivid and descriptive words to describe different seasons and weather phenomena, and "autumn tiger" is one of them.

02 How to identify the “ autumn tiger ” weather?

In meteorology, "autumn tiger" generally refers to the short-term return of heat after the beginning of autumn, especially after the end of the three-dog days, with temperatures above 35 degrees Celsius. "Autumn tiger" mainly occurs between the end of August and September of the Gregorian calendar every year, which is the transition period from summer to autumn .

The "autumn tiger" weather is usually characterized by cool mornings and evenings, hot and sunny afternoons, dry air and plenty of sunshine . In this kind of weather, due to the clear sky with few clouds and strong sunshine, the temperature will rise significantly, giving people a stuffy feeling.

The highest temperature forecast for August 25-26 across the country: many areas will still have a maximum temperature of over 40°C (Image source: China Meteorological Administration)

03 How is the “ autumn tiger ” weather formed?

The reason why the "autumn tiger" appears is mainly due to the subtropical high pressure .

In autumn, the subtropical high pressure in the western Pacific Ocean that controls China should gradually move southward, but this process is not smooth and sometimes fluctuates , so it rises northward again . Then, the weather in the area controlled by the subtropical high pressure is clear with few clouds and strong sunshine, which causes the temperature to rise.

The pressure belts and wind belts on Earth (Image source: "General High School Curriculum Standard Experimental Textbook: High School Geography Compulsory 1")

04 Will there be obvious regional differences in the “ autumn tiger ” weather?

China has a vast territory, and the "autumn tiger" in the south and north manifests itself differently. The "autumn tiger" in South China usually comes later than that in the Yangtze River Basin, generally delayed by 2-4 solar terms .

Forecast of high temperature areas on August 21 (Photo source: China Meteorological Administration)

The "autumn tiger" in the southern and northern regions is related to many factors such as climate, topography, and ocean influence. The southern region is characterized by long-lasting high temperatures, hot and humid weather, frequent thunderstorms, and lush vegetation ; while the northern region is characterized by mainly dry heat , frequent cold air activities, and relatively low high temperature intensity . This difference reflects the diversity and complexity of China's climate.

The duration of the "autumn tiger" varies from place to place, ranging from half a month to two months . Sometimes the autumn tiger comes and goes, and then comes back again.

05 How to take precautions against the “ autumn heat ” weather?

To prevent the "autumn tiger", you need to take measures from many aspects, such as preventing heatstroke and cooling down, adding clothes at the right time, replenishing water, adjusting your work and rest schedule, paying attention to healthy diet and proper exercise, so that your health and quality of life will not be affected by the "autumn tiger".

◎ Continue to prevent heatstroke . Although we have entered autumn, the temperature is still high when the "autumn tiger" hits, so we should not relax our efforts to prevent heatstroke. We should keep indoor ventilation and use air conditioners, electric fans and other equipment to lower the indoor temperature. At the same time, we should try to avoid outdoor activities during the noon period to reduce the risk of heatstroke.

◎ Pay attention to weather changes . In autumn, the temperature difference between day and night is large, and the temperature is lower in the morning and evening. Therefore, you should carry a coat with you when you go out so that you can add clothes in time according to weather changes to avoid catching a cold.

◎ Adjust the home environment . At home, especially at night, you should pay attention to the room temperature to avoid setting the air conditioner to too low a temperature, which may cause your body to get cold.

◎ Increase your water intake . As the weather gets drier after the end of the dog days, the human body is prone to dehydration, so you should increase your water intake. Adults should drink about 1500 to 1700 ml of water per day, and pay attention to the principle of drinking small amounts, multiple times, and slowly .

The weather is getting drier after the end of the dog days, so you should drink more water (copyright image from the gallery, reprinting may cause copyright disputes)

◎Replenish electrolytes . When working or exercising in a high temperature environment, the human body will sweat a lot, resulting in the loss of electrolytes. Therefore, while replenishing water, you should also replenish electrolytes appropriately, such as drinking light salt water or sports drinks.

◎Diet adjustment . The diet should be light, and spicy, hot, and greasy foods should be avoided to avoid adding burden to the body.

◎ Eat more fresh fruits and vegetables. Eating more fresh fruits and vegetables can meet the nutritional needs of the human body and replenish minerals such as potassium lost through sweating.

◎ Ensure adequate sleep . Adequate sleep helps the body recover and improves immunity. During the "autumn heat", you should appropriately extend your sleep time at night and take a short nap in the afternoon ( preferably no more than 30 minutes ) to relieve the "autumn fatigue" phenomenon.

◎ Adjust your work and rest schedule . Since the sun rises later and gets dark earlier in autumn, you can adjust your work and rest schedule appropriately, go to bed early and get up early to adapt to seasonal changes.

◎ Exercise moderately . Proper exercise helps to enhance physical fitness and immunity. During the "autumn heat", you can choose to exercise in the cool morning and evening hours in sports that are suitable for you, such as jogging, mountain climbing, walking , etc. However, it should be noted that you should avoid excessive fatigue and excessive sweating during exercise to avoid catching a cold or suffering from heat stroke.

Author: Wang Yuanhong, Senior Weather and Climate Engineer

Produced by: Science Popularization China