What does the last sentence mean, after the rain clears, after the fog clears?

The last sentence is that it will be cloudy if it is sunny for a long time. These two sentences mean that the fog will turn cloudy after a long sunny day, and will clear up after many days of rain. There is a weather proverb that it will be cloudy if it is sunny for a long time, and it will be sunny if it rains for a long time.

Reflecting the changing law of the weather, human beings have been trying to make accurate weather forecasts for thousands of years. Weather proverbs are proverbs summed up by working people's oral notes and history, which are used to indicate whether it will be sunny or stormy tomorrow. Fog refers to the weather phenomenon that there are countless small water droplets or small ice crystals suspended in the air near the ground, resulting in horizontal visibility less than 500 meters.

Proverbs about meteorology are:

1, ants move the snake aisle, there will be heavy rain tomorrow.

If ants are busy moving and snakes cross the road, there will be heavy rain tomorrow.

2, the morning glow never dies, and the sunset glow travels thousands of miles.

Meaning: If the sky is red in the morning, then the sky in the east is clear, so the sun can shine into the foggy sky in the west. On the contrary, in the evening, the sky in the west of Wan Li must be cloudless in Wan Li, so that the sun can shine into the clouds in the east through the sky in the west.

3, the sunset is carmine, no rain and no wind; The stars are shining at night, and the sun is still shining in the Ming Dynasty. The dew is heavy tonight and the sun is red tomorrow; The rainy mountain wears a hat, but the rainy mountain has no waist.

Meaning: When the sun goes down, it is crimson. This shows that the atmosphere contains more water vapor and impurities, so blue light is completely scattered by the atmosphere, leaving only red light with the longest wavelength, so the color of the sun we see is carmine.