How to Use Barometric Pressure, The Moon, and Forecasts to Catch More Fish

You might have all the right gear. Like a boat loaded with electronics, high-end rods and reels, countless trays of tackle, and lively bait, but that doesn’t guarantee success. Same goes for trips rod-in-hand down the bank to primo shore fishing spots. You might be totally prepared for success with all the right tools, but there are three factors at work on any given fishing day – weather, barometric pressure, and moon phase – that have a significant impact on catch rates. 

The unfortunate reality is most anglers have to work jobs, too, so it isn’t a matter of fishing whenever the mood strikes. When do we get to fish? When we have time to fish amidst work, family, and life obligations. But all that said, the onX Fish app can be a great tool for forecasting what day or days (even hours) might be best to fish, accounting for weather, moon phase, and barometric pressure. Planning ahead can definitely put the odds in your favor. 

How Weather Affects Fish Behavior

Like most creatures, fish are sensitive to weather and their behavior varies depending on it. 

Generally speaking, sunlight causes fish to seek out shade and shade lines where they can position themselves to feed and avoid other predators. Cloud cover is a good thing, and fish will roam more freely when the sun isn’t shining through the water’s surface. 

When it comes to water temperature, different species have varied tolerances. Again, generally speaking, the colder the water, the slower the fish metabolism, and vice versa. While most gamefish will feed in cold water, you might notice that you need to put the bait right in front of their faces as they are not apt to expend too much energy chasing their prey. Keep in mind this is when finesse tactics come into play. 

Speaking of cold fronts – drastic drops in air and water temperature during times of relative stability – fish will behave neutral to negative, not necessarily feeding. Same goes for warm fronts. But approaching storms with falling barometric pressure can trigger fish to increase activity and feed heavily. 

Is Fishing in the Rain Good or Bad?

Fishing in the rain needs to be handled cautiously. If there are indications of strong winds, lightning, or other weather that could put you at risk, it’s best to stay on shore. Still, fishing in rain not accompanied by lightning or larger storms can be exceptional because the influx of water introduces more oxygen which can increase fish activity. Rain also breaks up the surface of the water making them less shy about moving around to find prey, which can often be found around areas of current like streams, creeks, culverts and even storm drains where prey can be washed into the water for fish to feed upon. Barometric readings generally align with rain, too, if the system is smaller – and lasts for hours to days before worse weather and storms you would not want to fish in. 

Understanding Barometric Pressure

Barometric pressure is simply the weight of the atmosphere pressing down on a given point, measured by a barometer, which is filled with mercury. High pressure generally indicates fair weather while low pressure is a sign that storms or changes in weather may be approaching. 

Barometric pressure affects fish through their air (swim) bladders, the buoyant organ by which they stabilize and adjust to various pressures in the water column. Low pressure often cause fish to move deeper in the water column as well as toward shallower waters to feed while high pressure may send the same fish higher and into suspension in the water column to maintain equilibrium. During times of high pressure, fish are less apt to feed due to conserving energy and can be more difficult to catch. Again, think finesse fishing tactics during these times. 

Best Barometric Pressure for Fishing

So, what are the best barometric readings (which you can find on the onX Fish app) for fishing? Readings below 29.90 inHG are on the low end; readings above 30.12 inHG are on the high end. Readings between 29.90 inHG and 30.05 inHG generally indicate stable conditions for fishing, with fish active and feeding. Above that is considered high pressure and may turn fish neutral to negative. 

Fishing Times and Barometric Trends

In terms of barometric trends, falling pressure generally indicates fish becoming active and feeding while rising pressure can do the opposite. But the barometer isn’t the only indicator of what will turn fish “on” or “off”. Monitoring moon phase as well as moon majors/minors, as well as fishing during lowlight periods around sunrise and sunset can further put the odds in your favor no matter what the barometer is doing. Combine all these factors and you could have stellar fishing! 

How Moon Phase Affects Fishing

Like barometric pressure, the moon phase has impact on fish behavior. Fishing a couple days up to a full moon, during the full moon, and a couple days after can be exceptional for the nighttime angler, with fish feeding under the light of the sky and less during the day. But fish might not feed as much during the day during these times since most of their hunting is done at night. 

During a New Moon, fish don’t get much light at night and feed heavier during the day. So, combine the right barometric readings and a new moon and you put the odds in your favor for fishing banker’s hours. 

Waxing and Waning periods between the New Moon and Full Moon can bring about short windows of feeding, typically during early morning and late evening, with fish feeding during the day as well. 

There are also Major and Minor feeding periods to consider with the moon phase. Major periods mean the moon is directly overhead, while Minor means it’s entering or exiting the horizon – moonrise or moonset – both times when fish can become active. 

Let’s say you’re trolling at night for big walleyes. You’d want to orient your fishing during the Major period which often brings on feeding with the most light penetrating the surface and revealing prey to walleyes. Other fish, too, can become active at night – like crappies – meaning you could get into a flurry of bites with the moon directly overhead. 

How to Read and Use Fishing Forecasts Using onX Fish

If you’re looking for how to monitor weather, barometric pressure, and moon phase all in one place, click here to discover the many benefits the onX Fish app provides to align fishing trips with optimal weather windows. Rather than having to rely on several weather apps, a fishing map app, and other applications, it’s ALL right there at your fingertips in a one-stop-shop with onX Fish!

Final Thoughts

Looking to boost bites on your next fishing trip? If possible, plan your time around the most favorable weather, barometric pressure, and moon phase. Sounds good, right? Well, it’s not always easy to schedule time on the water during maximum percentage windows. The best call? Go fishing whenever you can, look at the data, and keep a journal to chronicle your successes and failures, which will eventually reveal patterns. The best way to do all of the above? Use the onX Fish app to fill you in with the data needed to make the most of your time on the water! Now get out there and have fun!