What does it mean that the sun turns into rain overnight?

One night, the hot sun turned into rain, dreaming of cool clothes. Overnight, the long-awaited rain suddenly fell in the clear sky under the scorching sun, and I woke up in my sleep, only feeling comfortable.

The origin of the poem: the poet of the Song Dynasty-the previous work: Su Daozhi, the original text of the whole poem is as follows:

Su Daozhong

Song dynasty-once upon a time

On the road, it rained heavily for three days on the night of July 25, and Qiu Miao and Sue were very happy together.

One night, the hot sun turned into rain, dreaming of cool clothes.

Don't worry about the bed leaking wet, like the depth of the stream.

Thousands of miles of rice flowers should be beautiful, and the leaves of Wu Gengtong are the best sounds.

There is nothing like dancing, let alone looking forward to the New Year on the field.