How to understand the saying in the countryside "There is no heat in summer, and the grain will not bear fruit"? Is there any scientific basis for this statement?

? I think this sentence has scientific basis.

If the weather is not hot enough in summer, the crops in the field will not grow well and the grain harvest will not be good.

We all know that the great summer heat is one of the 24 solar terms. The great summer heat happens just before and after the Mid-Autumn Festival in the dog days, that is, when the weather is the hottest and the temperature is the highest, that is, when the temperature is the highest, the crops grow fastest. But at the same time, various meteorological natural disasters will occur in many places.

For most of us, if it is very hot in summer, we will feel very uneasy. I feel that this hot weather will pass soon. I can't wait to blow the air conditioner directly at home, and I don't want to go out at all. I'm walking outside in the sun. Moreover, the bigger the sun, the stronger the ultraviolet rays. People will almost get a tan if they stand in the sun for a short time. I have a deep understanding of tanning.

I spent my summer in the village, because it was cool to live in a cave in the village in summer. My mouth shouted that I wanted this hot weather to pass quickly, but my uncle said, let it get hotter, so that crops will grow well, and you will have a good harvest in autumn, and you will eat a lot of delicious food.

Only when farmers are hot enough in summer will there be a good harvest in autumn. If summer is as pleasant as spring, crops will not grow well.

The above is my own understanding, summer is not hot, and there are many grains. I hope it helps you.