What can be used to express the hot and cold weather?

The degree of hot and cold weather can be expressed by temperature. The temperature mentioned in the weather forecast refers to the air temperature measured in the open air without direct sunlight (usually measured by blinds). The highest temperature is the highest temperature in a day, generally appearing in14-15; The lowest temperature is the lowest temperature in a day, usually before sunrise.

Daily changes, the highest temperature is around 2 pm, and the lowest temperature is around sunrise. The annual change shows that it is the hottest in July, the coldest in June, the hottest in August and the coldest in February in the northern hemisphere in 65438+ 10. The southern hemisphere is opposite to the northern hemisphere.

Measurement method

The ground temperature generally refers to the atmospheric temperature at a distance of 1.25-2.0 meters from the ground. When measuring, in order to prevent the influence of solar radiation on the observed value, the temperature measuring instrument must be placed in the shutter or radiation protection cover, and the measuring element must be well ventilated.

The main instrument used by the Meteorological Observatory to measure the near-surface temperature is a glass tube thermometer filled with mercury or alcohol. Because the thermometer itself absorbs more solar heat than air, and the reading indicated under direct sunlight is often higher than the actual temperature of the air around it, when measuring the air temperature near the ground, the thermometer is usually placed in a louvered box with ventilation on all sides about 1.5m from the ground.

These thermometers or thermometers are made according to the thermal expansion and cold contraction characteristics of mercury, alcohol or bimetal as sensors. The ground temperature mentioned by the meteorological department refers to the temperature in the louver at a height of about1.5m.