Why is it so rainy in spring?

In spring, the cold air in the north gradually weakens, and the warm and humid air flow from the Pacific Ocean in the south gradually strengthens. Warm and humid airflow will push from south to north, forming frontal rain at the intersection of cold and warm air. At this time, the intensity of cold and warm air is quite the same, so it will continue to rain. If the warm and humid airflow is strong enough to push the cold air to the north, the rain belt will move to the north.