Why You Should Tap Your Barometer

May 12, 2025

If you’ve ever noticed someone gently tapping the face of their barometer, you may have wondered what purpose it serves. This curious habit serves a significant purpose; lightly tapping your barometer face helps to maintain accurate ongoing readings, whatever the weather!

Here is why you need to tap your barometer:

Most traditional aneroid barometers use a sealed metal chamber containing a flexible capsule. This capsule expands and contracts as atmospheric pressure changes. These subtle movements are transferred to a needle on the dial, which indicates whether the pressure is rising or falling.

Typically, the needle displays pressure readings between 960 and 1060 hPa (hectopascals). Readings above 1015 hPa usually indicate high pressure, often linked to settled, dry weather, while readings below 1000 hPa suggest low pressure and potentially more unsettled conditions.

Although barometers are highly accurate, the mechanical movement inside can sometimes cause slight friction, which may prevent the needle from responding instantly. Gently tapping the face of the barometer helps to release this friction, allowing the needle to move freely and provide the most accurate reading. Since barometers magnify small changes in pressure on the dial, this simple action can help confirm whether the pressure is rising or falling.

How and when to tap your barometer:

If you are a new to barometers, here is how to make tapping a useful part of your weather watching routine:

· Tap gently! Using only your finger or knuckle, no more than twice, there’s no need to knock!

· Tap before you make a reading, especially if the weather feels like it’s changed (cloudier, windier, or even warmer).

· Track the needle movement immediately after tapping, observing whether the needle has shifted towards rising pressure or falling pressure. The direction in which the needles shift indicates what weather is coming. (High pressure indicates ‘good weather’ such as clear skies, and calm conditions. Low pressure indicates more unsettled weather is approaching, with a high chance of rainfall and windy conditions.)

This spring has proven that this trick is still useful:

Spring 2025 has been filled with long periods of settled high pressure and above-average temperatures across the UK. For avid barometer users, this meant slow and subtle changes, instead of dramatic needle shifts. During these periods, a well-timed tap is essential for detecting even the slightest changes in atmospheric pressure.

The ClimeMET barometer range:

At ClimeMET we provide a range of reliable and accurate barometer dials. Available in a variety of styles suitable for any weather watcher's wall.

The Barometer Dial CM4300

Our 9-inch barometer dial can be used either indoors or outdoors to measure air pressure. Set in a weather-resistant casing, with a personalisation option, our barometer dials are available in a variety of colours!

Traditional Wooden Barometer CM4202:

A solid wood weather dial, with a brass-plated dial and cream face. A traditional spin on our classic barometer weather dial, with a personalisation option, our wooden barometer is suitable for indoor use only.

Banjo Barometer CM4280/81:

Our Banjo Barometer range measures barometric pressure, humidity, and temperature. With lacquered brass bezels, exposed dial workings, and a mahogany stain finish. Our banjo barometers are the perfect traditional statement piece to place in your home. Personalisation is available, and our Banjo Barometers are suitable for indoor use only.

All barometers are tap-friendly!

FAQs:

Do I really need to tap my barometer?
Yes, if you're using a traditional aneroid (mechanical) barometer, a light tap can help the needle respond more accurately to changes in air pressure by overcoming slight internal friction.

Will tapping damage my barometer?
Not at all. ClimeMET barometers are designed with robust, high-quality materials. As long as you tap lightly, it's perfectly safe and in keeping with how these instruments are traditionally used.

Can I use a barometer to forecast local weather?
Yes! barometers give real-time insights into air pressure changes that directly relate to your local weather. They can often tell you more about what's happening outside than a generalised forecast app.

Where should I place my barometer indoors?
Choose a spot away from direct sunlight, radiators, or windows. Sudden temperature changes or drafts can affect accuracy. Ideally, mount it on an internal wall in a hallway, living room, or home office.

Can I hang a barometer in a conservatory or greenhouse?
We recommend avoiding areas with strong temperature swings or high humidity, as they can affect readings. A well-ventilated utility room or indoor wall nearby is often more suitable.

How often should I check my barometer?
Daily checks at ideally the same time each day. Over time, you'll begin to recognise patterns and build your own sense of what pressure changes mean for your area.