Inside Edge

Feeling the Pressure

It has long been known that barometric pressure has an effect on fishing. Exactly how it affects fish is still not fully understood, but an understanding of how to use barometer readings can greatly increase your chances of catching fish.

Barometric pressure is the measure of the weight of the atmosphere. It exerts pressure on us and the waters we fish. It can even change how well some people feel. It’s believed by many that it may have a similar and even more dramatic effect on the feeding habits of fish.

The measurement of barometric pressure is accomplished with the use of a barometer. A barometer measures the weight of the atmosphere per square inch and compares it to the weight of a column of mercury.

Barometric pressure varies with altitude. A higher elevation will have less atmosphere above it which exerts less pressure. To keep readings standard across the world, barometric pressure is indicated at sea level. Measurements at other elevations require a corrective factor which is based on elevation and air temperature.

Barometric pressure changes as the weather systems over us change. A blue H or a red L on a weather map indicates areas of high or low barometric pressure. The areas with high pressure are typically the areas with fair weather, and the areas with low pressure are areas with inclement weather. Barometric pressure has been used by weathermen since the beginning of meteorology to predict the weather. It can also be used by fishermen to predict the quality of fishing, and more importantly, is a valuable tool for helping us know how to fish.

It is important to note that the effects of barometric pressure are greater in shallow water than it is in at greater depths. This is likely due to the fact that the
pressure of water is so much greater in deeper waters making the air pressure above it have less impact.

Some general rules regarding barometric pressure include:

Pressure Trends	Typical Weather	Fishing Trends	Suggested Tactics
High	Clear	Slow down, fish cover or deep water.	Use baits more attractive to fish like jigs and soft plastics
Rising	Clearing or improving	Fish tend to become somewhat active.	Fish with brighter lures and near cover at intermediate depths.
Normal	Fair	Normal fishing	Experiment with your favorite baits.
Falling	Cloudy	Most active fishing	Use fast lures. Surface and shallow should work well.
Low	Rain/Storms	Fish tend to become less active the longer this period remains	As the action subsides, try fishing at deeper depths.

It is important to note that after a long feeding period, the action will slow regardless of other conditions. On the flip side, a long period of poor fishing conditions may be followed by a really good one.

The barometric pressure is just one of the many factors that affect fish feeding habits. Others include water temperature, light intensity, water clarity, PH level, water levels, wind/surface disturbance, boat traffic, fishing pressure and so on.