What is the specific situation when visibility is less than 200 meters in some areas of Beijing?

The Beijing Meteorological Observatory updated and issued an orange warning for heavy fog at 06:15 on October 19. It is expected that from now until the morning of the 19th, there will be thick fog with visibility less than 200 meters in most areas of the city. Please pay attention to precautions.

The Municipal Meteorological Observatory announced at 6:00: Today the fog will become clear during the day, and the north will turn to the south wind at Level 2, with a maximum temperature of 18°C; at night, it will become clear and cloudy, with light fog or mist, and the south will turn to the north wind at Level 1. The lowest temperature is 9℃.

In the yellow warning for heavy fog, the visibility is less than 1,000 meters and the local visibility is less than 200 meters, which will have an adverse impact on the morning peak. Please pay attention to traffic safety when traveling. Heavy fog orange warning and defensive measures:

Since last night, light rain has fallen in the Beijing area. This afternoon, the precipitation gradually ended. It is currently expected that there will be another light rain on Saturday, and the weather will be mainly sunny to cloudy for the rest of the week. Affected by the rainfall, the overall air quality in Beijing today is good to lightly polluted. The air will be level 4 moderately polluted for the next two days tomorrow, and will improve to level 2 good on the 22nd.