At some level, I have known for a long time that barometric pressure impacts fishing and fish activity. Changing pressure has a way of making fish bite. That was about the extent of my knowledge. It wasn’t until recently that I decided to dedicate the time to taking a deep dive on the subject.
I made the call after a frustrating ice fishing trip. A group of friends and I were fishing a local lake that I had only spent a little time on. We were marking plenty of fish, but couldn’t manage a bite. We spent hours with our flasher screens lit up like Christmas trees only to repeatedly watch the marks float toward our bait and then float away.
As we headed back to the landing, tails between our legs, we had a brief conversation with another fisherman who was making his way off the ice. He said he caught seven small panfish, but that was it. “It’s the high pressure,” he said. “It just shut things off.”
After every fishing trip, I have a debriefing meeting in my head. I think through went what right and what went wrong and begin to formulate plans for how I am going to change things the next time around. Much of the night following this trip was spent scouring the internet for background information on the relationship between barometric pressure and fishing success.
My research continued into the following days. I even invested in a pocket barometer that now accompanies me on every fishing trip. I’ve learned a lot since that frustrating ice fishing outing and this new knowledge has helped me catch more fish or, at the very least, helped me better understand why I’m not having any luck.
Consistently catching fish can be difficult and anglers should use every tool at their finger tips to increase their chances of success.
Here’s what you need to know to start using shifts in barometric pressure to your advantage.
Why barometric pressure impacts fishing
I began my research by challenging the credibility of the collective assumption among anglers that barometric pressure impacts fishing. It didn’t take long to establish there is plenty of science to confirm this.
The next question became: why?
In order to survive, fish must be able to detect a host of subtle changes to their environment. Shifts in pressure are on that list.
While fish can sense changes in atmospheric pressure with their lateral lines, they can also feel these changes in their swim bladders. Essentially, swim bladders are an organ that control the fish’s buoyancy.
As atmospheric pressure moves in a given direction, the fish’s swim bladder must do the opposite to compensate. This can lead to discomfort for the fish and lead it to move shallower or deeper, depending on the situation.
But there is something much larger at play here. Let’s take a step back and look at the bigger picture.
Barometric pressure also impacts the fish’s prey. This is an important component as fish need to eat to live. As such, they will never stray too far from their next potential meal.
Phytoplankton and zooplankton make up the bottom of the food chain. Even small changes in pressure can affect the location and behavior of these microorganisms. As the plankton begin to move, so do the minnows and other fish that feed off it. This has the potential to change the feeding patterns of the baitfish which, in turn, alters the movements of the game fish.
What barometric pressure means for fish activity
So what should you be looking for before you head to your favorite lake or river? It depends who you ask.
While there is something to be gained by understanding the current pressure situation, you will see that it is more about exploiting pressure trends. If your weather app of choice doesn’t provide you with this information, consider investing in a hand-held fishing barometer to stay on top of things.
The exact numbers you are in search of may vary by source. But here are some general rules of thumb to get your started:
High pressure (30.41 mbar or higher): Fish action is slow-to-medium, adjust presentation speeds and bait sizes accordingly.
Medium pressure (29.62-30.4 mbar): Fish are in their “regular” patterns.
Low pressure (29.61 mbar or lower): Fish become sluggish, downsize and slow down. Don’t be afraid to fish deeper or seek out structure.
Consistent pressure generally means typical levels of fish activity. However, over long periods of time, lack of changes will ultimately slow fishing. The best action comes when anglers take advantage of shifting barometric pressure. Here is what to look for:
Rising pressure: Fish become slightly more active.
Falling pressure: Fish activity is high, but only for a brief period of time. Capitalize while you can.
Keep in mind, barometric pressure is just one of many factors that play into angling success. Weather, time of day, fishing pressure, and technique are also critical variables.
However, learning how to cash-in on pressure patterns will go a long way in helping you make the most of your time on the water.