Understanding How Pressure Determines Your Success

Authored By Todd Heitkamp

As you’re reading this, think of the last time you went fishing. Did you listen to the weather forecast before heading out?

If so, did you listen for the barometric pressure?  Was the pressure falling or rising?

You may be thinking to yourself, “Why would I listen for that?” or “I never hear or see a forecast for pressure”.  Both are valid questions or statements.  But the one thing you may not know is that pressure and whether or not it’s rising or falling can decide or at least influence your success on the ice or open water.

There have been days that we all can relate to when the fishing has been extremely slow. You have to admit that sometimes you come away scratching your head saying, “Where were the fish?”  Especially, if you had great success the previous day on the same lake using the same presentation. So what changed from one day to the next? As most people do already, you could blame it on the weather. And most likely, it’s not due to a significant change, but more often only a change in the air pressure can determine your success. So let’s take a closer look at the pressure and its affects.

As a cold front approaches the area, the pressure will be falling and the wind will be out of the south. Once the front passes, the wind becomes northerly and the pressure then begins to rise. In between these two states of the atmosphere, the barometric pressure will usually hold steady for a period time. 

The key to your fishing success is to watch the changes in the barometric pressure. In other words, is it rising, falling, or holding steady? When you think of pressure think of weight measurement, as the barometric pressure reading is actually the weight of the atmosphere. So when the pressure is falling, the atmosphere is lighter and conversely when the pressure is rising, the air becomes heavier. This change to the weight of the atmosphere or pressure exerts a force on the earth’s surface. Humans and animals, including fish, feel the effects of these changes in pressure.

When the pressure is rising, the fish are driven into deeper water and become even more lethargic because their bladder enlarges to stay buoyant. This enlarged air bladder takes up more space in the body of the fish, so they feel full and less likely to feed. On these days, you have to go looking for the fish! The changes in pressure or the force that is exerted has more influence in the winter than in summer due to the ice taking up more volume to the lake. Plus, fish in shallower bodies of water are affected more than those in deeper lakes. With a river, like the Missouri River, it seems as if the pressure changes have less effect on the fish within the system due to the existence of the river current. The species of the fish can also make a difference. It seems that pike are least affected by the changes, where the perch “family”, which includes walleyes, is most affected. But honestly, we’re still learning.


The hours leading up to a frontal passage can be some of the more successful periods a fisherman can have due to the “feeding frenzy” of the fish. I call these days our “full bucket days”. This theory has been put to the test many times. On many occasions, my boys and I would hit the lake and take note of the pressure and the expected time of the front moving through the area. We didn’t have to move around to find the fish, they came to us. On the post-frontal days (pressure rising), we weren’t as successful and we had to move around quite a bit to find the more aggressive fish. These days are what we call our “empty bucket” days. A person has to work harder during these slower periods to find and ultimately catch fish. The effects of the pressure can easily be seen by watching your flasher.  On these high pressure days, fish can be enticed to come up off the bottom and investigate your lure or bait. But after a brief investigation, the fish drops back down to the bottom without touching your bait.

Or in some cases, the fish won’t come off the bottom at all. You can see the bottom flicker on your flasher, so you know fish are there, but they’re not interested in feeding at all! Changing the presentation by “downsizing” may help, but more often than not, a person has to be mobile and go look for the fish that may be a little more aggressive. Take your auger in one in hand and your flasher in the other and go search for those aggressive fish. Plus, you may not be able to stay in one spot as the aggressive fish will have left or been caught after a period of time. If a person sets up camp before searching for the fish, they need to watch their flasher and be ready to move if the flasher doesn’t indicate fish. I usually give it 30 minutes. If I don’t mark a fish within that time frame, I move to a different location. Time on the ice is short, so fully utilize every minute by using your flasher and become more efficient.

So, the next time you’re planning your fishing trip, listen to the forecast. Since there is no pressure forecast, listen to the wind forecast. If the wind is out of the south, the pressure will be falling and you should experience one of those “full bucket” days. If a northerly wind is forecast, the pressure will be rising and you’ll need to “search” for the fish to avoid the “empty bucket” syndrome. You can get the latest weather forecast at www.weather.gov or on many weather apps that are available today. If you want to see the 3-day history of the pressure changes, you can also get that information from National Weather Service websites.

Remember, the weather is just one factor that can influence your success but it’s one factor that is often over-looked and cannot be changed. I would like to say that everyone needs to try to “time” their fishing trips to coordinate with the days with falling pressure, but obviously that’s not possible. If you’re like me, you go when you can go.

Therefore, it’s important to know what the pressure is doing and be able to adjust your presentation while on the ice. Many of the recent advances in fishing technology have made it easier to minimize the number of “empty-bucket” days. But ultimately it’s left up to only one thing – us!  Good luck and as we say around here – Fish On!!

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