What does it mean to have good weather in the first frost?

If it is a warm sunny day with the first frost, it indicates that winter will not be too cold, but it will be warm.

The appearance of "warm winter" not only indicates that there will be less rain and snow in that winter, but also "spring drought" and "cold spring" in the coming year. "The first frost is sunny and the spring is chilly" means that the warm weather in spring is conducive to the growth of crops, but if there is a sudden sharp cooling, it will have a great impact on the wheat that has turned green and the fruit trees that have entered the flowering period, leading to a large-scale reduction in production. Therefore, people don't want a "cold spring" in spring.