Understanding Barometric Pressure: How Does It Affect Fishing

Kristian Ole



Did you know barometric pressure is one of the factors that influence fishing? As an angler, you may catch massive fish one day and bomb the next despite fishing in the same area. This is all effectuated by numerous factors, including barometric pressure. Keep intact to learn how barometric pressure affects the catching of fish.

Barometric pressure is the force of the air at sea level; hence any fluctuation in atmospheric pressure would affect life under the water. Fish can sense when the barometric pressure is about to drop. Fish will tend to respond to the change via feeding patterns. The high atmospheric pressure of above 29.92 in-Hg makes an excellent opportunity for fishing. Rapidly falling pressure offers the best period for fishing. Low pressure lets anglers go slow in deeper water as fish are slightly active. Fishing is more reliable when pressure is constant for several days.

Knowing how the weather and barometric pressure can affect fish is imperative in standing a better chance of reeling target catch. If you wish to know the best barometric pressure for fishing, scroll within the post as we peruse to discover the interrelationships.

Barometric Pressure and Fishing

Barometric pressure is a force created by the weight of the air within the atmosphere. Temperatures in the earth’s surface combined with the earth’s movement result in the creation of either low or high pressure. Barometric pressure varies across the globe.

Atmospheric pressure affects what is above and below the water. You can use traditional barometers or advanced smartwatches/ smartphones to measure barometric pressure. Commonly used barometers include aneroid and mercury barometers.

An aneroid barometer assesses air pressure by expanding metal, and mercury barometer computes barometric pressure by adjusting the level of the mercury in a tube.

Barometric pressure can be defined in different units such as Pa, hPa, mm Hg, psi, in-Hg, or millibars. Standard barometric pressure is 1013.25 hPa/ 101325 Pa/ 1013.25 millibars/ 760 mm Hg/ 14.696 psi/ 29.9212 in-Hg.

At sea, barometric pressure ranges 14.7 pounds per square inch. The barometric pressure at higher elevations is usually lower than the sea level pressure.

Fluctuation in barometric pressure indicates movements of weather systems and fronts. High pressure accompanies calm, clear, and dry weather whereas low pressure accompanies windy, cloudy, and wet weather.

Barometric pressure ranging between 29.70 and 30.40 inches of mercury offers the best fishing condition.

During this medium pressure, an angler can carry out regular fishing or try out some new techniques. When the readings on the barometer dips below 28 inHg, fish in deeper waters.

Choosing a Barometer to Measure Atmospheric Pressure

  • The barometer must be highly accurate. The excellent quality instrument works to demonstrate significant pressure fluctuation. If the capsule seal fails, the tool is dead. If the capsule features un-uniformed thickness, the readings may not be reliable.
  • Consider the altitude, especially if you plan to use it outdoors. Actual atmospheric pressure reads equivalent to sea level. Barometer works that atmospheric pressure decreases with an increase in altitude. 

How Does Barometric Pressure Affect Fishing?

Barometric Pressure and fishing

Mass of air in the atmosphere is held on the water surface; hence, adding weight to the water column above the fish. The atmospheric pressure increases as you go more profound because of the higher water column on the water surface.

Fish species have air bladders that fill with air to aid them in maintaining buoyancy and swimming up and down the water column. Air bladders are affected by changes in barometric pressure. An unfavorable change in atmospheric pressure leads to fish altering their behavior.

Drop-in barometric pressure leads to inflation of the bladder. A significant drop in pressure makes the fish swim deeper to feel better. Divergently, higher pressure reduces the size of the air bladder.

Barometric pressure alteration affects the behavior of the fish; hence, anglers should change the lures they are used to. Shifts in atmospheric pressure mean that the fish will tend to feed more, especially before the arrival of a storm and after the storm passes.

When the barometer indicates a drop in pressure after a session of high pressure, you can easily lure the fish with faster bait as it is likely to chase it down. During this condition, the fish will be actively feeding prior to the onset of the low pressure in which they are less active.

As the barometric pressure starts to rise after a bad storm, some fish may take longer adjusting to the rising pressure. They may take up to 24 hours after the storm to feed again. Savvy anglers hit the waters during rapidly falling pressure.

Offshore fish species may not always be affected by fluctuation in barometric pressure; rather, their feeding behavior may be affected because of the prey they feed on. When prey senses a change in air pressure, they may head to deeper water.

Barometric pressure effect on fishing is intertwined with other changes in weather, precipitation, wind, and solunar cycles. Prolonged periods of high pressure may potentially mean that fish can be found in the water column.

What is a Good Barometric Pressure for Fishing?

As an angler, it is imperative to know when to head out for that catch. The best conditions for fishing are during normal barometric pressure or when the pressure is dropping. When the pressure is changing, especially the dropping period, fish are usually very active. Thus, you can use faster lures and fishing techniques.

Anglers like to fish before the storm when the atmospheric pressure is dropping. When the pressure drops to lower values, try to present your bait deeper. During high barometric pressure, fish are usually slower and moderately active.

Fish will sense rising air pressure; thus, they will feed heavily for the coming days. During this time, they can be easily lured to the bait. On the other hand, fish like to move when atmospheric pressure is failing. Thus, you can engage in drawing them on topwater.

Adjusting fishing tactics based on the atmospheric pressure parameters boosts the chances of getting more catches. Fishing charts portray certain barometric pressure conditions and fishing activity related to it. Below is a simple barometric fishing chart to help you during a fishing situation.

High/ lowBarometric pressureFish Activity
High30.50 and aboveFish are usually slower, moderately active, feed halfheartedly, and will most likely stay near the bottom.
Medium29.70 – 30.40Perfect, normal fishing conditions. Use different baits and gear to meet the needs of the fish.
Low29.60 and belowFish are usually less active, nervous, spook easily, and bite slowly. Go at the fish slowly in deeper water or near cover.
RisingImproving weatherFish are slightly active but slow. They may gather in one area the whole day.
StableFairweatherGood, normal fishing conditions. Fish aren’t interested in eating. Try different gear or baits.
FallingDegrading weatherBest fishing conditions as fish are likely to strike anything they get. Fish are inactive movements.

High Barometric Pressure

Both normal barometric pressure and changes in barometric pressure offer ideal fishing conditions. Let’s see the variance between low pressure and high atmospheric pressure fishing.

High barometric pressure is above 30.5 inches of mercury. It offers a perfect time to fish from a boat as the water is calm. It is vital to integrate the lunar phase, use tides and time of day to your advantage, and in turn, fish efficiently on high atmospheric pressure. The elements can be used to predict where the fish might be found.

High atmospheric pressure fishing is convenient for you, but the fish may be slower than usual. Clear skies and calm wind accompany high barometric pressure. As much as the weather is good, the mild conditions may not trigger the fish to make lots of bites on the lures.

If you target fish during high atmospheric pressure, search for fish in deep waters or around hiding places. During this time, the fish is resting in some safe place, and it is not actively feeding. Getting a catch at high pressure will be slow and more challenging than normal pressure.

You can quickly identify high atmospheric pressure through birds as they merely float on top of the water. Use dead or cut bait as easy prey to lure fish during high pressure. Extended periods of high barometric pressure take into account your fishing technique rather than the behavior of the fish.

Related article: Get better results using a fishing thermometer

Low Barometric Pressure for Fishing

Low atmospheric pressure is termed when reading is less than 29.60 of mercury. During this condition, the sky is cloudy, and there is the presence of rain. As much as the fish may be less active during low barometric pressure, you can use the condition to your advantage.

Cloudy skies block sunlight penetration; thus, you can immerse slow baits into the water if you have found where the fish are hiding and get a chance to catch a fish. The failing pressure just before a storm will trigger immense activeness in the water, hence, best atmospheric pressure for fishing.

During a low atmospheric pressure period, fish tend to hide out in deeper areas of the water. The fish are not actively feeding; hence your fishing success rate may not be as high.

How Does Barometric Pressure Affect Fish?

Even the slightest change in barometric pressure will change the behavior of the fish. Change in atmospheric pressure initiates changes in gravitational balance in the water. Fish may weigh less and be prone to ups and downs.

Fish are attentive to their ecosystem; hence they coalesce sensing systems that quickly detect slight changes in the atmosphere. Fish through the lateral lines can detect vibrations in the water. When the weight of the air above changes, the pressure of the water against fish bodies fluctuates.

Largemouth bass, crappies, and walleyes are affected by pressure changes. The bony fish species use the swim bladder to regulate their buoyancy and depth levels without swimming. Change in pressure results in pressure being exerted on the fish swim bladder.

Fish in shallow water are more susceptible to changes in barometric pressure than fish in deep water. Rapid changes in the pressure displace the zooplankton and phytoplankton; thus, a feeding wave is created between the fish used as baits.

When plankton and small food items are moved in the water column, atmospheric migrations also occur. The fish that feed on the planktons move too. This results in the movement of some species higher in the water column or deeper in the water. The pressure-induced migrations encourage/discourage feeding.

A slight drop in barometric pressure can lead to materials floating to the bottom or rising higher in the water column. Falling atmospheric pressure spurs walleyes to feed, switching from live bait to crankbaits.

Low-pressure systems such as major cold fronts will shut down fish activity. Change in barometric pressure results in pressure on the fish swim bladder, making it feel uncomfortable. When fish experience a change in atmospheric pressure, they are usually not driven to feed; instead, they find a spot deep enough to relieve the pressure on their bladders.

Fish with larger swim bladders such as trout, snapper, and grouper feel the effects of fluctuations in atmospheric pressure differently. Fish with smaller bladders like kingfish and barracuda are not affected by a minor change in pressure. Sharks and tuna species lack swim bladders; thus, fluctuation in barometric pressure may not affect their swimming or feeding behavior.

After a day or two after a storm has passed, fishing can turn out to be a success as the fish will start to move again.

Related article: The ideal fishing depth for crappie

Using Barometric Pressure to Find Feeding Times

Barometric parameters can aid you in bettering your fishing success. It is ideal for savvy anglers to add discerning elements to their repertoire. That being said, you can easily find your fish by reading barometric pressure.

  • Fish usually prefer to feed during periods of stable pressure. Cold fronts are usually preceded by low atmospheric pressure; thus, fish start to feed gluttonously upon sensing a drop in barometric pressure. Identifying their location during this period, you are bound for a huge catch.
  • Once the pressure drops, feeding ebbs, and fish move to deeper areas to stabilize their organs. During this period, the fish are inactive in terms of feeding. It takes between 24 to 48 hours to experience another fierce feeding.

About Kristian Ole

Kristian Ole Rørbye, a marine biologist and seasoned angler, shares his fishing adventures and expertise on FishingKris. Join him as he explores the world's waters, one cast at a time.

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