Because there are mountains in the west and north of Beijing, after the cold air comes, it sinks and heats up on the mountains. All cold air heats up first, then cools down, and turns cold in the morning and evening. Under the control of cold air mass and clear sky radiation, the basement temperature dropped obviously, creating temperature conditions for today's snowfall.

According to the Beijing first snow standard of Beijing Meteorological Observatory, when snowfall is observed at more than 10 of the 20 artificial stations in the city; Or 5 stations in the urban area (Chaoyang, Haidian, Fengtai, Shijingshan and Meteorological Observatory) observed snowfall; Or when snowfall is observed at three or more of the five stations in the urban area, and the snowfall at least at 1 station is ≥0. 1 mm, such snow is defined as the first snow.

Pay attention to safety in snowy days;

1, don't put your hands in your pockets when you walk, or you will easily get hurt when you fall.

Be extra careful when going up and down stairs or steps. It is best to hold handrails or other fixtures.

3. Don't chase and fight on the slippery and icy road, otherwise it will easily cause injuries.

4. When walking on ice and snow, it is best to wear non-slip rubber shoes, try not to wear flat shoes without patterns, keep your body center of gravity low, and always pay attention to driving conditions.

When crossing the road, you should stand on the side of the road and adjust the angle of your hat and umbrella to avoid blocking your sight. Only when there are no vehicles coming around can you pass carefully.

6. Don't run in a hurry, don't cross between two cars, and don't suddenly change the direction of walking or retreating.