Is it possible that the weather in Beijing is as humid as that in Chengdu?

That's impossible. Beijing has a typical monsoon climate, while Chengdu is much less affected by the Siberian cold current.

Chengdu is not only rainy, but also short sunshine time, low wind and humid air, but it is a bit excessive.

In winter in Sichuan province, it is rainy and cloudy. When I entered Sichuan in winter, I didn't see the moon for 20 days, and the sun was rare. Even if I saw it, it was covered with dark clouds.