What do you mean, sunny and rainy days are just a moment?

Sunny and rainy days are just a moment, indicating that the weather is changeable.

This usually refers to summer. One second it's sunny and the next it's raining cats and dogs, which describes the unpredictable weather.

Weather refers to the specific state of the atmosphere near the surface in a short period of time. Weather phenomenon refers to various natural phenomena in the atmosphere, that is, the comprehensive expression of the spatial distribution of various meteorological elements in the atmosphere (such as temperature, pressure, humidity, wind, clouds, fog, rain, flash, snow, frost, thunder, hail, haze, etc.). ) in an instant.