What do you mean, the signature is hidden in the rainbow, but it's not a light snow?

It means that the rainbow is gone, just like it is hidden. It's time for a light snow.

I can't see the rainbow. "Rainbow" here refers to the rainbow after the rain. Generally, in summer, rainbows occasionally appear under the action of sunshine after rain, and the appearance of rainbows requires rain, sunshine and temperature.

After the arrival of the light snow solar term, the temperature is very low, and the rain will form ice and snow at low temperature, so there will be no rainbow at this time. "The rainbow disappears" should mean that the rainbow disappears after this season, just like hiding.

Extended data

The phenological phenomenon reflected by the light snow is that the rainbow no longer appears, and the yin and yang are up and down, which makes it difficult to communicate with each other, resulting in everything being lifeless, as if it were blocked. This is the arrival of winter.

In the traditional concept of our country, "heaven" is the god of the sun and "earth" is the god of yin. Therefore, during the light snow festival, yang will rise and yin will fall, because yin and yang cannot rise and fall, and it is difficult to achieve balance, which is what we call the imbalance between yin and yang, which leads to lifelessness. This is a major climate feature of Xiaoxue solar term.