The weather forecast says it rains every day, not once. What happened?

The weather forecast is only a forecast of the average atmospheric conditions in recent days, including atmospheric temperature and precipitation.

Atmospheric precipitation has three necessary conditions, one is cooling, the other is combining with condensation, and the third is saturated air. If these three conditions are met, it will bring some precipitation.

If the result of rain is not clear, these three conditions have not been fully achieved or all of them have achieved such a result.