Fishing after heavy rain is an option. Heavy rain will bring nearly saturated oxygen into the water and replenish dissolved oxygen in a short time. Fishing often works well during this period. Windy weather is also one of the options. Air dissolves its oxygen in water by touching the water surface, which is one of the sources of dissolved oxygen, and the wind undoubtedly intensifies this process. Downward flow and shallow water should be supplemented first, with the highest dissolved oxygen content, and downward flow and shallow water should be used as fishing spots. Even if the breeze blows, the dissolved oxygen content in shallow water is the highest. As long as the water temperature in shallow water is not too high, the fish mouth will not be broken, but the number of fish in shallow water is small. Another source of dissolved oxygen is photosynthesis of aquatic plants. The algae family in "fat water" is very prosperous, so the dissolved oxygen content in shallow water is high enough. However, if there is no wind, the convection of water body is very weak, and the dissolved oxygen in shallow water layer can not replenish the whole water body in a short time. In some particularly "fat" waters, the fishing time of fish is only ten minutes before dark. At night, the sunlight disappears, photosynthesis stops, and algae begin to die in large numbers and sink to the bottom. It not only no longer produces oxygen, but also consumes a lot of oxygen during its degradation. Therefore, the fatter the water, the less suitable for night fishing.