How is the air quality in Hangzhou? Is there haze?

The air in Hangzhou has always been good. I remember the foggy days many years ago. It is usually warm from the end of June, 5438+February to June, 5438+1October before the arrival of cold air, but now the air quality and environmental management in Hangzhou are well controlled. There was no fog in the early days, but there was water and fog. The West Lake has blue sky and clear water all year round.