The appearance of the hydra is indeed a precursor to a storm. Before it rains, there will be air pressure and lack of oxygen. Snakes will come out of their holes to get some air. Some snakes live in low-lying areas. After a heavy rain, water will accumulate in the snake holes, and snakes breathe with their lungs, so they will crawl out.
Of course, snakes will usually be forced out of their holes when the weather is particularly humid and hot. Therefore, when a snake comes out of its hole during the day, it is a sign of rain, especially when the weather is cold in late autumn and early winter. If a big snake comes out of its hole, it will rain in a day or two. This is the "big snake comes out of its hole, and there is heavy rain." "Verification of the performance of other small animals before it rains. The reason why it has this ability is that some of its organs can keenly sense changes in the water vapor content in the air.
