The answer is not a simple one because there are no absolute answers to why fish bite. But when something in the weather or environment is in transition, fish seem to react positively.
Let’s start with after it rains. Rain has a much bigger effect on saltwater fish than it does on freshwater fish. The main reason is that after it rains the salinity level of the saltwater will change. Salinity is important to saltwater fish especially flounder, trout and redfish. Not so important to snook and tarpon however, they can actually live in freshwater. Depending on how much it rains will determine the following for saltwater fish.
- How much the salinity level will change.
- How much the water temperature will change.
- How much the dissolved oxygen content will change.
- How much chemical runoff will be washed into the water.
- How much force will be added to the tidal current.
All of these factors will affect your bite with saltwater fish.
Now for freshwater fish only #’s 2, 3 and 4 will have an effect. As far as #5, sometimes it can create a current through creeks, drainage pipe outflows or even the rise of the lake, pond, or stream water levels.
Usually it is not the rain itself that has the before-or-after effect on the freshwater or saltwater fishing, unless it is a large amount of rain. It is the actual front and the changing of other weather variables just prior to or after the pass of the front where it rains that has the effect. During these times there is a rapidly changing barometer which changes many water and weather factors. So you should be fishing before or after the fronts whether it is raining during them or not. During these times the barometric pressure is rising and falling, which is good for fishing.
On another note, I personally enjoy fishing in the rain, when it’s cloudy, overcast and dreary. Not because the fishing is better, but there are less crowds. LOL Thank you for sending in your question to The Online Fisherman. Tell all your friends about us.
Captain David M. Rieumont
The Online Fisherman Inc.