The summer solar term is the period with the most sunshine and the highest temperature in a year in South China, the period with the most abundant rainfall, the most common thunderstorm and the most concentrated days with high temperature above 3℃ in the west of South China, and the period with the most frequent occurrence of high temperature above 35℃ in the east of South China.

The summer heat is also the season with the most thunderstorms. There is a proverb that says, "There is no drop of lightning in the east, but the lightning in the west can't walk", which means that in the summer afternoon, if lightning appears in the east, it won't rain here. If lightning is in the west, it will come soon, and it's too late to avoid it. People often call the thunderstorm in summer afternoon "northwest rain" and describe it as "northwest rain, which falls on a car-free road."

"Summer rain across the ridge of the field" and "Summer rain across the back of cattle" vividly illustrate that thunder showers often rain here and clear there, just like the poem of Liu Yuxi, a poet in the Tang Dynasty: "It's sunny in the east and rainy in the west, but it's sunny in the road."