The author compares spring rain to smoke, from which we can realize the characteristics of spring rain.

The author compares spring rain to smoke, from which we can realize the thin and light characteristics of spring rain.

The spring rain described by the author is thin and light. From the outside, it looks like cow hair, like a flower needle, like a filament, and it is densely woven. There is a thin layer of smoke on the roof of someone else's house.

This is the description of spring rain in Zhu Ziqing's Spring.

Good rain knows the solar terms of rain, just when plants germinate and grow. It falls quietly at night with the spring breeze, beautiful and fiery red, and the whole Jinguan City has become a world with flowers in full bloom.