The weather forecast symbol ∞ represents haze.

Classification

1. Slight haze: relative air humidity is less than or equal to 80%, visibility is greater than or equal to 5 kilometers and less than 10 kilometers;

2. Mild haze : Relative air humidity is less than or equal to 80%, visibility is greater than or equal to 3 kilometers and less than 5 kilometers;

3. Moderate haze: relative air humidity is less than or equal to 80%, visibility is greater than or equal to 2 kilometers and less than 3 kilometers;

4. Severe haze: the relative air humidity is less than or equal to 80%, and the visibility is less than 2 kilometers. Extended information

1. Affects physical health. The composition of haze is very complex, including hundreds of atmospheric particulate matter. Among them, aerosol particles with a diameter less than 10 microns are mainly harmful to human health, such as mineral particles, sea salt, sulfates, nitrates, organic aerosol particles, etc.

Aerosol particles with a diameter less than 10 microns are Coarse particles, often referred to as fine particles with a diameter less than 2.5 microns, are inhalable particles (can be inhaled into the lungs), which can directly enter and adhere to the upper and lower respiratory tract and lung lobes of the human body.

2. Affects mental health. Due to the weak light and low air pressure caused by gloomy and hazy weather, it is easy for people to feel lazy, depressed and pessimistic, and even lose control when encountering unpleasant things.

3. Affect traffic safety. When haze weather occurs, outdoor visibility is low, pollution continues, traffic is blocked, and accidents occur frequently.

Baidu Encyclopedia-Weather Symbols