When we talk about pressure and fishing, we aren’t just referring to increasing our catch rate (especially when competing against friends).
It should come as no surprise to you that fish behavior is dramatically impacted by the weather. But what influences the weather?
The answer? Barometric pressure.
If it all sounds like voodoo to you, don’t worry, as it is about to become really clear.
Today, I will go through the best barometric pressure for fishing and tell you everything you need to know.
Table of Contents
- What is Barometric Pressure?
- High Pressure vs Low Pressure for Fishing
- What is the Best Barometric Pressure for Fishing?
- Barometric Pressure Fishing Cheat Sheet
- How to Keep Track of Barometric Pressure
- Best Barometric Pressure for Fishing – FAQ
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What is Barometric Pressure?
Barometric pressure is a measure used to determine the weight of the air pushing on a given area at a given time.
Traditionally, we measure this using an instrument called a barometer. In the past, this was a tube filled with mercury, with gradients of inches etched into the side.
Depending on the air pressure, the mercury would move up and down in the tube. To this day, meteorologists and observers still refer to barometric pressure using the term ‘inches of mercury’. It is denoted in the following format (in. Hg)
Air weighs next to nothing, right?
While air (or should I say its constituent parts) is made up of very light gases, you’ve got to remember that there is quite a lot of air above your head, and the weight of this air adds up. We call this the atmosphere.
The atmosphere is made up of a variety of elements. This includes oxygen, carbon dioxide, and nitrogen, not to mention hydrogen and water vapor! You won’t be able to feel the weight of all these elements.
Because over billions of years, life has evolved to consider it ‘normal’. However, it is there. How much does ‘standard’ barometric pressure weigh?
You might be shocked to learn that on each and every square inch of your body, there is a force of about 15lbs pushing down.
That’s about the same as a bowling ball!
The pressure of the air changes vastly from day to day. It is affected by temperature and huge global forces.
Because the sun heats only one side of the earth at a time, different surfaces, such as the sea and land, heat up at different rates. This heats the air above, too, resulting in pressure differentials. It’s what causes the wind and weather in a given place on a given day.
The long and short of it?
These pressure differentials, along with the associated weather, have a direct impact on your fishing.
For now, let’s keep it simple and say this.
During high barometric pressure conditions, you can expect relatively clear weather. During low-pressure conditions, you can expect unsettled weather.
The effect of barometric pressure on your fishing?
High Pressure vs Low Pressure for Fishing
But, Bob… Fish live in water, not global air masses, so it doesn’t matter, right?
Wrong, my friends!
High Pressure vs Low Pressure which is best for fishing?
In most cases, high-pressure days will outfish low-pressure days
Fish are just as affected by barometric pressure and the weather as we are. For a variety of reasons. Let’s look at a few.
Low Barometric Pressure and Fish Physiology
First, let’s talk about bladders…
No, we aren’t talking about taking a bankside whizz… I mean swim bladders.
All fish have a swim bladder. This is an inflatable sac within the body of the fish. To control their level of buoyancy and stability, fish can slowly inflate and deflate their swim bladder. It’s full of air!
Let me ask you something.
Have you ever been on a flight? The air pressure at altitude is much lower than on the ground. Ever noticed what happens to a bag of chips while in these low-pressure conditions? They swell up, right?
Exactly the same thing happens to the fish’s swim bladder when air pressure is low. Unlike you or I (much to the annoyance of our partners), fish can’t easily regulate the internal air pressure of their innards. As a result, they feel discomfort when the air pressure is low.
This causes two key behaviors.
The first is that fish will head into deeper water. This compresses their swim bladder, making them feel a little more comfortable.
Second, they will feed less vigorously. After all, would you like to chase your dinner when you’ve got a bloated stomach?
Remember what I said above. As a general rule, the weather conditions during bouts of low pressure will be worse?
This also has a direct effect on fish feeding behavior.
Here is the weather commonly associated with low pressure:
- High winds
- Tall, billowing clouds and rain
- A drop in temperature
All of the above makes fishing challenging. If there is a lot of rain going into the water, it can cool it and switch the fish off feeding. In rivers and streams, it can cause an increase in volume. This means the fish have to fight harder to maintain their position, expending energy.
In short, they hunker down.
Don’t get me wrong, you can catch fish in the rain, but you need to look into what you’ll be facing. Luckily I’ve got a great guide to fishing in the rain right here.
As a result of the above, you’ll find that the action may slow down or even stop completely when fishing in low pressure.
This isn’t only true when the air pressure is low, but also when it is dropping. Fish have a sixth sense for the weather and will take cover before storms and when low-pressure hits.
High Pressure Equals Good Weather – Most of the Time
When looking at high pressure and your fishing, we can assume all of the opposite, with a few exceptions.
High pressure will bring the fish up in the water, meaning they are much more active and likely to feed.
The same can be said of rising pressure too.
The weather associated with higher pressure is much more conducive to a good day’s fishing too.
Think clear skies, light winds, and warmer days.
A Good Rule of Thumb – How Does Barometric Pressure Affect Fishing?
Keep an eye on the pressure and the forecasts.
If the pressure is high or on the way up, this is a great time to go fishing.
If the pressure is low or on the way down, manage your expectations as fishing will be markedly worse.
What is the Best Barometric Pressure for Fishing?
If you want a good place to start, anything from about 29.80 inHg and 30.30 inHg is good for fishing, regardless of species.
This will pretty much ensure that the weather is pretty stable, not too bright, not too bad, and it won’t have a ruinous effect on the fish’s swim bladder.
Is it optimal? Probably not. Are the fish always present during these conditions? Almost always, yes.
While the above rule of thumb is a good place to start, you should know by now that there are always exceptions in fishing.
The truth is it depends on the species you are trying to catch.
Here’s a handy guide to give you the best barometric conditions by species.
Best Barometric Pressure for Bass Fishing
- Pressure: 29.99 to 30.99 inHg.
- Look for Trend: Sustained High or Rising.
- Hardest During: Sustainedlow Pressure.
Bass tend to be caught during rising and high-pressure conditions.
During the warmer months, they are predominantly surface and upper water feeders. As a result, you are going to struggle when they are forced deeper by low-pressure conditions.
What’s more, high pressure brings bright and clear weather conditions that are just perfect for bass fishing. It means the water will be clearer, your lures are more visible, and the bass will be feeding much more actively.
Best Barometric Pressure for Walleye Fishing
- Pressure: 29.53 – 30.99 inHg.
- Look for Trend: Sustained high and falling.
- Hardest During: Sustained low pressure.
Walleye are real predators and can generally be caught during the entire range of most barometric conditions.
But I’m going to let you in on a secret.
As I said above, high pressure brings periods of settled weather. If you fish for walleye during these periods, then you will have a pretty good day out.
Want an unforgettable day out?
Keep an eye on the weather and the pressure and follow this advice.
Try and time your visit when the pressure is falling after a long period of settled high-pressure weather. I’m talking 6 hours or so before a storm is due to hit or right after.
Here’s a quick guide on how to fish before or after the rain.
For some reason, walleye go absolutely crazy during these periods, and you’ll easily be able to reach double figures if you time it right.
Best Barometric Pressure for Crappie Fishing
- Pressure: 29.92 – 30.50 inHg.
- Look for Trend: Medium pressure or high and falling.
- Hardest During: Sustained high and sustained low pressure.
Remember how I said that generally, high-pressure conditions are good for fishing?
Crappie are one of the exceptions.
Crappie tend to be pretty hard to catch during high-pressure weather conditions.
It’s more to do with the weather.
Crappie like to take shelter during those clear and still sunny days and will generally head to deeper water until the light conditions fade. You could try tempting them out of the weeds with a lure, but fishing in the upper levels of water just isn’t going to work.
So, what barometric conditions are the best for catching crappie?
The guidance I gave on low pressure still stands. Crappie will be switched off during sustained low-pressure conditions. You want to catch them during transitory periods or those of middling air pressure.
If the pressure is rising steadily or falling steadily, these are the best times to give crappie fishing a go.
Best Barometric Pressure for Catfishing
- Pressure: 29.53 – 30.99 inHg.
- Look for Trend: Rising from a sustained period of low pressure. Or from high to low.
- Hardest During: Sustained low pressure.
I love catfishing for a few reasons. The first of which is that they put a serious bend in my rod.
Because they tend to feed deep on the bottom, catfish tend to be pretty impervious to pressure changes.
They aren’t bothered by strong sunlight, churned-up water from storms, or by anything but the lowest pressure.
The best barometric pressure for catfishing tends to be either immediately following a low-pressure period. Or transiting from high through to low. Unless you are fishing in the middle of a storm, this essentially means that you can fish for catfish pretty much any time.
Best Barometric Pressure for Trout
- Pressure: 29.00 – 29.92 inHg.
- Look for Trend: Low pressure transiting to high, high pressure just before a storm.
- Hardest During: Sustained periods of high pressure.
Trout are another one of the exceptions.
I’ve caught trout on foggy days, cloudy days, rainy days, windy days, storms…
Let me tell you when I hardly ever catch trout.
Bright, cloudless, sunny days.
For that, you can read ‘high pressure’.
Trout hate bright conditions and can be extremely hard to catch when there isn’t a cloud in the sky. If you do want to fish for trout on high-pressure days, either go late at night or early in the morning.
As for the best barometric pressure for trout, I’ll say this. Anything other than sustained high pressure will allow you to catch. Trout will feed in the rain and on low-pressure days. They will also feed ferociously during changeable conditions.
Barometric Pressure Fishing Cheat Sheet
Feeling a bit like a weatherman?
Alright, I get it. And I want to help you guys catch fish easily.
Here’s a quick reference barometric fishing chart that will help you quickly identify barometric pressure and what species can be caught.
Air Pressures Definitions:
- Low: 29.00 – 29.53 inHg
- Mid: 29.53 – 30.12 inHg
- High: 30.12 – 30.99 inHg
|Species||Good Barometric Pressure for Fishing (inHg)||Optimal Weather||Optimum Barometric Pressure Trend||Worst Conditions|
|Bass||29.992 – 30.99||Improving or brightening conditions. Calmer days.||Pressure rising. Low to high||Sustained low pressure|
|Walleye||29.53 – 30.99||Sustained periods of bright and clear days.||Sustained high pressure going to low||Sustained low pressure|
|Crappie||29.92 – 30.50||Generally settled weather, occasional showers.||Mid pressures either rising or falling||Sustained high pressure, sustained low pressure|
|Catfish||29.53 – 30.99||Changeable conditions.||From low to high or high to low||Sustained low pressure|
|Trout||29.00 – 29.92||Any conditions apart from clear skies.||Low to high or immediately following a high||Sustained high pressure|
How to Keep Track of Barometric Pressure
Yes, I know…
All of the above is good and well, but how do you actually know what the pressure is?
Well, relax. I’m about to show you a few different ways you can keep track.
Observation of the Weather
While this is the most readily accessible way to get a good idea of what’s going on, it isn’t actually the best… Unless you want to become a meteorologist.
You can observe certain signs in the weather that will tell you what is happening to the air pressure.
Days with slack winds and cloudless skies tend to be high-pressure days. If it is foggy in the morning, that is also a great indicator that the day has started off with high pressure. If there is cloud on high-pressure days, this will be a high-level overcast layer.
Low-pressure days are characterized by the presence of wind. Ever seen clouds that look like huge puffy cotton balls. These are called cumulus or cumulonimbus, and they are a surefire way of seeing that the air pressure is low.
My advice would be to watch a weather station. Often, they will state whether there is a high or low-pressure air mass moving into the area where you intend to fish. And if not, by the forecast, you’ll be able to make a semi-accurate assessment of what the air pressure is likely going to be doing based on what you see.
A barometer can exist in many forms. The simplest, which we’ve mentioned, is a calibrated tube filled with mercury.
No, don’t worry. You don’t need to use these anymore.
You can get analog barometers that contain different metals that are pressure-sensitive. These are great as they tell you the current air pressure. Some also come with trend information telling you whether the pressure is rising or falling.
Some fancy ones even have a little needle that points to what the weather will be like.
They can be a little inaccurate.
Do you think that the air pressure where you are now is the same as the air pressure where you might be going?
Barometers are only good if they are used in the same location as you intend to fish. And I don’t expect you to carry a barometer with you when you head out to go fishing.
Fortunately, there is another much more reliable solution…
Welcome to the 21st century, my friend, and thank you for joining us!
Nowadays, we don’t need to mess with tubes of poisonous metals or stand peering at steampunk dials and needles. We’ve got mobile devices!
Mobile devices can take and aggregate pressure from different sources and place it at your fingertips. Satellite imagery, weather sensors located globally, and multiple reports are all yours for the taking.
And the best bit?
There are loads of weather apps specifically for fishing! Some even have a diary feature where you can log your catch and the conditions at the time, so it can be repeated at a later date!
Which apps are the best for fishing?
Well, you are in luck as I reviewed all of the best fishing apps just over here.
Best Barometric Pressure for Fishing – FAQ
Listen, air pressure and weather phenomena are tricky subjects, so you are bound to have questions.
Want some simple, straightforward answers? You are in the right place. Here’s what people normally want to know.
What is Normal barometric pressure?
I’m glad you asked.
Normal barometric pressure is referred to in what is now known as the international standard atmosphere (ISA). Consider this a bit of a benchmark, or in other words, the exact point that scientists and weathermen use to describe ‘average’ air pressure.
What is it?
Well, on a barometer, it is described in two ways. Over here in the US, we use “inches of mercury” as our standard unit of measure. ISA pressure is 29.92 inches of mercury. Our friends over the pond in Europe use a different scale called hectopascals (hPa). The standard ‘normal’ barometric pressure is 1013 hPa.
Both 29.92 inHg and 1013hPa are the same. They are both the ISA mid-level pressure.
Is fishing better during high or low pressure
If you asked me overall, I’d say that high pressure will outfish low pressure 9/10 times. The odd outlying species that won’t feed at either extreme of the scale are trout and crappie.
However, that puts you in quite a good place.
Why? With the other species, such as bass and walleye, provided that the pressure isn’t at its lowest, you stand a reasonable chance of catching fish. And if that doesn’t work, well, you could always have a go at catfish instead.
Is 30.2 barometric pressure high?
Yes, this is high pressure. Remember, the middle of the scale sits at around 29.92 inHg. This is well above that mid-point. It isn’t the highest pressure you will encounter while fishing, but it is certainly above the mid-level.
Feeling under pressure? Don’t. Knowing the best barometric for pressure doesn’t need to be overly complicated. Avoid extremes at either end of the scale, keep an eye on the weather, and know that transitory conditions are good for most fish, and you won’t go far wrong.
If you want to up your game, check my quick reference guide above for optimal pressure conditions. If you are going to be fishing in the rain, you might want a decent jacket. Check out my top suggestions for fishing rain gear right here.