Since the beginning of summer, high temperatures have been continuously occurring in various parts of China. The high temperature in the south continues, and the North China region has experienced prolonged hot and humid weather. The Central Meteorological Observatory predicts that in the coming week, regions such as central and southern Hebei, Huang Huai, Jianghan, Jianghuai, northern Jiangnan, Guanzhong in Shaanxi, and the Sichuan Basin will experience sustained high temperatures of over 35 degrees Celsius, with some areas reaching a maximum temperature of 39 to 42 degrees Celsius. At 18:00 on July 14th, the Central Meteorological Observatory issued an orange warning for high temperatures. The weather is stuffy and hot, and there is always a public feeling that 'why is it hotter than the forecasted temperature?' What is the reason for this? The observation environment of meteorology is different from an individual's outdoor environment, so people often feel that the predicted temperature is different from their physical perception. ”Zhu Dingzhen, a specially appointed expert at the Meteorological Propaganda and Science Popularization Center of the China Meteorological Administration, said. According to the regulations of the World Meteorological Organization, the temperature released by the meteorological department is the temperature measured by the thermometer in the louver box. The louver box should be placed on the lawn, 1.5 meters above the ground, with a relatively open environment and no tall buildings or trees blocking the wind or sunlight. However, within the same city, the temperature in the louver box is different from that on the cement road and asphalt road. In strong sunlight, the temperature at a height of 1.5 meters on cement and asphalt roads may be 4 to 5 degrees Celsius higher than the temperature measured in the louver box. Differences in road conditions and surrounding environments can cause variations in temperature measurements. As for the temperature that everyone feels, that is, the perceived temperature, there is greater uncertainty. ”Zhu Dingzhen said that perceived temperature is the temperature that everyone feels after coming into contact with the outside air, and is influenced by many factors such as air pressure, wind speed, humidity, etc. Firstly, individuals have different perceptions of temperature depending on their objective environment, such as whether they are in a park or a bustling city, or in a well ventilated or enclosed environment; Secondly, there is a close relationship between perceived temperature and atmospheric humidity. As long as the temperature reaches around 33 degrees Celsius and the relative humidity reaches 80%, people will feel very hot and humid. This year, the subtropical high pressure system jumped north earlier and showed a trend of westward extension, with a relatively large "body". At the same time, under the control of the southward airflow on the edge of the subtropical high pressure system, water vapor transport is very sufficient, resulting in relatively high relative humidity. Beijing and other places experienced hot and humid "sauna days" earlier. Experts remind that the large-scale high temperature weather process in the central and eastern regions has a long duration and a wide range of impacts, with obvious humid and hot characteristics in the south. The public should minimize outdoor activities as much as possible. Personnel working under high temperature conditions and those who need to work outdoors for long periods of time during the day should take necessary protective measures. At the same time, energy supply and human health protection measures should be taken in various places. Not long ago, the National Center for Disease Control and Prevention and the China Meteorological Administration jointly issued the first national level high-temperature health risk warning and health alert. Unlike general weather forecasts, warnings are divided into 5 levels and are based on risk analysis of diseases related to high temperatures. The public can take corresponding measures according to the risk level, including keeping indoors cool, avoiding going out during high temperature periods, reducing outdoor activities, ensuring sufficient drinking water, etc., to better prevent the adverse health effects caused by high temperatures. (New Society)