Have you noticed that bass behave differently when a storm is about to approach? This is due to the change in barometric pressure. The fish feel it, unlike us, and react to the change. Pro angler, Mike Iaconelli, said he gets the best bite when the barometer is falling, or low and steady. That is usually when a front is approaching, and bass become active. When the pressure is rising or high and steady, the fish are not very predictable. Sometimes they move into cover other times they go into deep water.
What is happening to the bass when the pressure changes? Well there’s no scientific evidence of a direct correlation between changes in barometric pressure and bass behavior. But many of us will attest to the different ways bass react to pressure changes. As the pressure gets higher, bass move to deeper water to escape the feeling. Some say that a bass’s swim bladder is sensitive to these changes, thus they try to swim a way from it.
Ralph Manns wrote an article for In Fisherman explaining his field studies on just this topic. He found that when the barometer read less than 29.30, about 27% of bass fed on the surface away from the shore. This was greater than the 18% of feeding observed when the barometer was higher than 29.70. He also found that 36% of observed bass were feeding during high barometer readings compared to just 30% at low readings.
Then he looked at actual strikes and lure refusals and found that 52% of bass struck during low readings compared to 39% at high. But then he said the majority of strikes were during barometer readings of 29.30-29.70, neither high nor low.
When the barometer was rising, no observed bass were schooled, while 20% schooled when the pressure was falling. He says that, “If it weren’t for other factors affecting bass activity, the data might suggest that a falling barometer, approaching storm, increasing cloudiness, or a combination of these and other factors increased feeding activity.”
It seems like there’s a bit of evidence for changes in bass feeding and behavior due to barometric pressure changes. Even if there is no research stating a direct correlation, many of us rely on these pressure readings and get good bites out of them. So it’s up to you to decide if you want to include these readings into your bass fishing strategy.