What is a barometer, and what it measures

You may have heard the term barometric pressure or barometer come up when the weather is being discussed or simply when you’re on a flight. A lot goes into predicting weather conditions, and barometers are a huge part. In this article, we’ll take you through what a barometer is and what it measures.


A barometer is a device that measures atmospheric pressure. The normal barometric pressure at sea level is 30 PSI, which is where it is measured.

In this article, we’ll also go over the following topics:

What is a barometer, and what does it measure?

Vintage Weather Station

A barometer is a device used to measure atmospheric pressure. The atmosphere includes the air that is wrapped around the earth. Due to the pull of gravity, this air varies in parts of the earth. It’s different at land, sea level, and high above the clouds. Atmospheric pressure is this weight that is a result of gravity. Barometers measure this.

This figure is important as it affects the weather. Hence meteorologists must use it to accomplish their readings of the weather.

How they work?

The earliest form of the barometer is the mercury type. The barometer is a tube closed at the top but open at the bottom. The mercury sits in a shallow dish. When the atmospheric weight is less than the weight of the mercury, the mercury rises. The units marked are atm which is the average air pressure at sea level at a temperature of 15 degrees Celcius.

There’s also the aneroid barometer with a metal chamber to measure the atm. The chamber expands and contracts depending on the atmospheric pressure. The amount of contraction or expansion is measured, and thus the atm is determined. The atm is shown on a clock-like dial.

What is the barometric pressure today?

There is a way to find out your local barometric reading online. Not just this, you can check the reading for any state or location in your country. Here is a great site to monitor these readings.

Normal barometric pressure

Normal barometric readings are measured at sea level. The units measuring this are hectopascals, millibar, torr, and inches of mercury(psi). The normal pressure at sea level is 30 PSI. For a frame of reference, 1 atm = 14.696psi.

A high reading is about 30.7psi, while a low reading is below 27.3psi. An intensely high or low reading has several effects on the body. For instance, at higher altitudes, the pressure is less. Thus less oxygen is present. It means the heart must work harder to pump blood faster from the heart.

Low pressure causes tissues to expand. It means that any joints will face intense duress. You will likely feel worse if you’re already suffering from pain in specific joints.

Barometric pressure chart and normal ranges

Please look at our simplified chart to know what’s normal, high, and low. Also, for chronic migraine patients, a separate column indicates readings to watch out for.

Normal (in Hg)High (in Hg)Low (in Hg)Headaches (in Hg)Arthritis
Sea level3030.727.329.6827.3
1000 ft altitude2929.726.328.6829.7

Best aneroid barometers

Aneroid barometers have quickly replaced mercury ones. It is due to their portability and their sturdiness. A mercury barometer could not be transported easily without fear of the liquid spilling over or the fragile glass breaking and spilling its contents.

Here are some of the best aneroid barometers for your perusal.

Compass-like meter

This completely weather-resistant meter is guaranteed to meet all your expectations. It’s highly portable and won’t tarnish or scratch during travel. There’s even a lifetime warranty on finish and movement.

The brass finish gives it an excellent luster. It is worthy of a lifetime warranty because it won’t give away so soon.

You can mount it on a boat or land easily.

NameWeems and Plath
Item Dimensions LxWxH4.75 x 2.2 x 4.75 inches
Item Weight0.8 Pounds


  • It’s very stylish.
  • Good accuracy
  • It felt superior to other products we tried.


  • It’s not cheap.

Versatile and gift-worthy

It is just not a barometer. It’s also a thermometer as well as a hygrometer. That means it will be able to tell you not just the atm but also the temperature and humidity in your surroundings. The look is gorgeous and is perfectly sized at 5 inches for great visibility.

The gold finish is beautiful and makes it worthy of a gift to an avid fisher or climber.

You can also purchase it in the enticing silver color.

Item Dimensions LxWxH5 x 5 x 1.5 inches
Item Weight5.3 ounces
Special FeatureLightweight, Strong


  • Much cheaper than the previous option
  • Easy to read


  • Not as accurate
  • Not as well-built

Large monitor display

Now take pleasure in a large LCD without any complicated dials and readings. It is a completely wireless display that helps with easy movement. It has a weather display, temperature display, hygrometer, and barometer showing indoor and outdoor results.

It also shows the moon phase and has a backlight to monitor the screen anytime at night. You will be shown the weather prediction for the next 12 hours. What’s not to love?

NameBALDR Weather Station
Are Batteries IncludedNo
Barometer Range850-1050 hPa/mb
Display TypeLCD
Item Weight0.88 Pounds
Power SourceAc
Wireless Range330ft


  • It has many functions.
  • Good price
  • Easy setup


  • Not as stylish

Sleek and smart

Here is another LCD screen but with many additional features. You will receive a wireless remote sensor and a humidity and temperature monitor upon ordering. The remote sensor takes a reading at intervals of 57 seconds, so the readings are always as precise as can be. For more accuracy, the base unit supports more sensors if need be.

The LCD will show you the barometer, the calendar, the date and time, the temperature indoors and outdoors, the humidity indoors and outdoors, and the moon phase.

Are Batteries IncludedNo
Display TypeLCD
Number of Batteries2 AA batteries required.
Package Dimensions12.48 x 8.66 x 2.05 inches


  • Very elegant
  • Great price


  • Not as classy as the alternatives

How to read a barometer

wall clock barometer

Even though you might know what it is and what it does, you might not know how to read a barometer. Here’s how it is done.

  1. Tap it

It sounds funny, but tapping the barometer before will release any residual energy and bring it to the reading.

  1. Find out the average.

Your barometer ought to be adjusted for the average pressure. You can find out the average atm for your area online. Note down the reading.

  1. Adjust the meter

Now adjust the barometer for the average reading by moving the dial. It should be done on a clear day without any storms coming.

  1. Reading

Now take the reading. Note where the needle is moving and whether it is stable or not. Note which millibar it sits on. Take the reading several times throughout the day. The weather will be stable if the reading is constant and unchanging. If the pressure changes with every reading, a storm is likely.

Remember that a barometer will help you determine the changes in weather in the future, not the current scenario.

Does barometric pressure affect arthritis?

Yes, certainly. High pressure causes the expansion of tissues, while low pressure causes contraction. These changes can cause stiffness, pain, and swelling in tissues, muscles, and tendons affected by arthritis.

Why do elderly and arthritis patients suffer more joint pain during winter? It is because the low temperature thickens the fluid in the joints. It makes the movement painful since they are stiffer.

In research, it has been reported that living in higher-pressure areas over two years did increase pain by a fraction. The difference is little, but it forces you to wonder where to settle as someone with arthritis.

Either way, changing weather and atm can mean pain, but when the weather settles in and becomes constant, your pain will likely even out.

Can barometric pressure cause headaches?


It’s not the atm itself but the change in pressure that causes a headache or migraine. The sinuses on your face and in your nose are filled with air. When the outside pressure changes, a difference is formed inside and outside the sinuses. This change causes many symptoms:

  • nausea or vomiting
  • headaches or migraines
  • pain in the temples
  • light sensitivity
  • neck and face numbness

Studies have shown that people with chronic migraines experience severe headaches with even the slightest drop in the barometer. They don’t have to be taking a flight to feel an induced headache. As a result, changes to higher pressure made them feel better.

What does a barometric pressure headache feel like?

Those who have the following symptoms are likely experiencing a barometric headache:

  • Eyes watering
  • Pain in and around the sinuses
  • Nose dripping
  • Pain in the temples
  • Nausea
  • Light and sound sensitivity
  • vomiting

It’s important to distinguish between a sinus headache and a pressure migraine. The symptoms above won’t be triggered by allergies or sinus issues.

Natural remedies for barometric pressure headaches

Here are some remedies and preventative measures to keep headaches at bay.

  1. Drink enough water

Changing weather is common in spring and fall when we approach the summer and winter, respectively. It’s important to keep your hydration level optimum in this period. Drink 7-8 glasses of water a day.

Drinking water is both a preventative measure as well as a cure. It is because most headaches are triggered by dehydration.

  1. Getting enough sleep

Some headaches can be slept off, so sleep can be a cure. However, not getting enough sleep can be an additional trigger for those sensitive to environmental pressure changes. If you know incoming changes in pressure are likely to affect you, getting enough sleep can limit the effects of the headache.

7-8 hours of sleep per night is recommended for adults between 18 to 60.

  1. Essential oils

Once you have a headache, few things can treat it naturally. Essential oils are one of them. Lavender, eucalyptus, and peppermint are known to be great when inhaled.

Rub some onto your temples and wrists and see if it helps. You can also mix them in some hot water and inhale them through steam. It will let the oil into your sinuses and help you balance the pressure. It should help you relieve stress as well.

  1. Magnesium

Magnesium deficiency is known to cause migraines. Increasing its intake will prevent and cure headaches as well. Magnesium can be found in supplements, but it is safer to go the natural way to avoid side effects like diarrhea.

Magnesium-rich foods are leafy green vegetables as well as whole grains. They can also be found in nuts like almonds and dried beans and legumes like soybeans, lentils, and peanuts.

  1. Cold compress

You can use a cold compress, like an ice pack or a pack of rice put in the freezer for some time, to soothe your headache. Apply this to your temples, the back of your neck, and your head for relief.

The reduction of inflammation and constriction of blood vessels makes the pain minimal for some time.

  1. Try caffeine

Sipping on some coffee or tea can benefit those going through a headache. Caffeine is known to improve mood and constrict blood vessels which aids in relieving headache pain. However, caffeine intake should be limited and not in excess.

Too much caffeine can also cause headaches if one is suddenly deprived of it.

  1. Acupuncture

Not many people are unaware of the Chinese therapy of poking needles into specific pressure points in the body to relieve many types of pain. Studies show that people with migraines have been known to benefit from this therapy.

If you don’t want to be popping ibuprofen all the time, this might be an effective natural remedy.

  1. Meditation and yoga

Many studies have shown that regular yoga can reduce migraines’ intensity, duration, and frequency. It relieves stress, another trigger of headaches, and keeps you physically and mentally fit.

How does the barometric pressure affect fishing?

It’s common to find barometers in fishing boats and aboard large fishing vessels as well. Why is this? How can pressure possibly affect your game?

It’s known that as pressure rises, fish will seek cover in lower depths. Falling pressure, however, will make them go to shallower water in search of food.

It is because gravity influences pressure in the water as well. Fish are very sensitive to environmental changes in the water. It is truer for smaller fish as they will be most affected. For instance, pressure changes can force deep-water fish to the surface because they are tiny and weightless compared to larger whales and sharks.

Thus if you are not equipped to handle the changes in the barometer, experts suggest sticking to the prime areas where there is an abundance.


Here are some commonly asked questions about barometers.

What is considered high barometric pressure?

A reading above 30inHg is considered high pressure. It translates to 102268.9 Pa or 1022.689 Mb.

What is considered low barometric pressure?

A Low reading is that which is below 29.80 inHg. It translates to 100914.4 Pa or 100.9144 Mb.

What level of barometric pressure causes headaches?

It is found that whenever pressure is about 6-10 hPa below the standard pressure, it is likely to induce migraines.

However, it can also be induced by small weather changes or seasonal changes.

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