A set of four-character idioms describing changeable weather

It's dark, cold and hot, lightning and thunder, yellow sand covering the sun, pouring rain, violent storms.

Impermanence _ Pinyin, an idiom to describe the changeable weather: biàn huà wú cháng

Interpretation: impermanence: there is no normality. Of things constantly changing and having no regularity.

Source: "Zhuangzi Tianxia": "The desert is invisible and unpredictable."

Example: Recently, the weather has been ~, with clear skies in Wan Li and downpours.

Unpredictable _ pinyin, an idiom to describe the changeable weather: biàn huà mò cè.

Interpretation: measurement: estimation. It changes a lot and is unpredictable.

Source: Yu's Epitaph of Ma Jun, a Small and Medium-sized Prison in the Temple: "When it is, I see Wang Yubei Pavilion, with a deep forest and dragons in the mountains, which is unpredictable."