Can frost really predict the weather? Is there a basis?

Of course it's true, there is a basis! The first thing to understand is how frost forms:

The formation of frost is not only related to the weather conditions at that time. When the surface temperature of the object is very low, but the air temperature near the surface of the object is relatively high, there is a temperature difference between the air and the surface of the object. When hot air comes into contact with the surface of a cold object, the air will cool down and the excess water vapor in the air will precipitate. If the temperature is lower than 0℃, the excess water vapor condenses into ice crystals on the surface of the object, which is frost.

In addition, clouds hinder the radiation cooling of ground objects at night, and clouds in the sky are not conducive to the formation of frost. Therefore, frost often appears on clear nights, that is, when the ground radiation cools down strongly.

In addition, the wind also has an influence on the formation of frost. When there is a breeze, air flows slowly over the surface of supercooled objects, constantly supplying water vapor, which is beneficial to the formation of frost. But when the wind is strong, because the air flows quickly, the time to contact the surface of cold objects is too short. At the same time, when the wind is strong, the air in the upper and lower layers is easy to mix with each other, which is not conducive to cooling down and will also hinder the formation of frost. Generally speaking, when the wind speed reaches level 3 or above, it is not easy to frost.

When straw is burned in the field at night which is prone to frost, the temperature near the surface increases and the air flow pattern near the surface accelerates. The smoke formed by combustion reduces the radiation cooling of the ground and destroys the frosting conditions, so it is not easy to frost.