The Best Galileo Thermometers

How they work and the best to buy

By Ed Oswald

Updated:

Reading time: 3 minutes

A Galileo Thermometer is a sealed glass tube filled with liquid, typically ethanol, with glass spheres filled with colored liquids and weights attached. As the temperature changes, the liquid expands or contracts, which allows the glass bubbles to rise and fall. The number on the metal tag of the lowest sphere is the temperature.

While the instrument bears the name of the great Italian physicist Galileo Galilei, he did not invent the thermometer. However, the physical principles he discovered some four centuries ago make this glass thermometer a reasonably accurate ambient temperature measurement compared to modern digital thermometers.

The Weather Station Experts participates in Amazon Associates and other affiliate programs and may receive a commission from clicking on links on our site.

In this article:

The Weather Station Experts’ content is supported by online advertisements.
Please consider supporting us by disabling your ad blocker.

Who invented the galileo thermometer?

Galileo thermometers are named after the Italian physicist Galileo Galilei. However, the instrument itself was created by researchers at the Accademia del Cimento of Florence sometime in the mid-1600s. One of the researchers on the team, Torricelli, worked with Galileo on research surrounding the concepts of the thermometer.

As the temperature of the liquid changes, the weighted spheres begin to move. While these thermometers are not particularly accurate, they are generally accurate enough to give an idea of your indoor temperature within a few degrees.

How to read a galileo thermometer

Galileo thermometers are unique devices that use the principles of both buoyancy and density to measure temperature. The thermometer consists of a glass container filled with a clear liquid and several spheres with weights of different densities. The weighted spheres are free to move up and down the glass container, each labeled with a different temperature.

As the temperature of the liquid changes, the metal balls either float or sink until they reach a position where the liquid has the same density as the metal ball. The temperature is read on the medallion of the lowest sphere.

Best Galileo Thermometers

Our Pick - Galileo Thermometers
Wind & Weather Galileo Thermometer
$34.99

This 20" tall Galileo thermometer is one of the larger models available and is perfect for an office or living room area.

Buy from Amazon Buy from Wind & Weather
We earn a commission if you make a purchase, at no additional cost to you.
01/26/2023 02:29 pm GMT

Wind and Weather have become synonymous with quality traditional weather instruments, and its 20″ tall hand-blown Galileo Thermometer is no different. However, given its height, you’ll need an open spot to place this one. But you’ll be able to read this one from a distance.

Lily's Home Round Galileo Thermometer
$49.95

Lily's globe-like design with this tabletop Galileo thermometer gives it a unique look.

Buy Now
We earn a commission if you make a purchase, at no additional cost to you.
01/26/2023 01:38 pm GMT

We like Lily’s Round Galileo Thermometer just because it’s different. Most thermometers you’ll see are long cylindrical tubes. Here, Lily has placed the thermometer inside a globe-like stand, which takes up less room. Reviews are pretty solid too, and it doesn’t seem to operate any less accurately than a traditional-style cylindrical Galileo thermometer.

AcuRite Galileo Thermometer with Glass Globe Barometer
$47.18 $34.99
  • Includes galileo thermometer and storm glass
  • Wooden base
Buy Now
We earn a commission if you make a purchase, at no additional cost to you.
01/26/2023 10:33 am GMT
galileo thermometer with blue skyImage Credit: Tiffany Means - stock.adobe.com

The Fitzroy Storm Glass

The Fitzroy Storm Glass is a weather forecasting tool used by sailors in the 19th century. The glass is filled with a mixture of water and chemicals, and the crystals that form within the glass can predict the weather. According to legend, the weather will be fair if the crystals are clear. If they are cloudy, then it will be rainy. If they are clear, then the weather is fair. While the scientific evidence for this claim is scant, many people still believe in the power of the Fitzroy Storm Glass. As a result, it has become a popular decoration in homes and offices.

Storm Glass Weather Predictor
$39.99 $31.99
Buy Now
We earn a commission if you make a purchase, at no additional cost to you.
01/26/2023 11:33 pm GMT

The Constantinople Storm glass is an excellent gift for weather geeks. With a simple yet elegant design, the Constantinople Storm Glass is a great decorative piece for the home that you can place anywhere.

More than a piece of home decor, the Constantinople Storm Glass is a “weather instrument” that predicts weather changes. The chemical mixture inside the glass experiences changes in crystallization based on weather conditions. For more precise weather forecasting, the weather glass should be placed near a window, outdoors, or in areas exposed to fresh air. However, there’s no objective evidence it works, but it’s a great conversation piece.

Lily's Home Analog Weather Station with Galileo Thermometer
$49.95

If you'd like both a Galileo thermometer and a Fitzroy Storm glass together in an attractive desktop case, this model gets great reviews.

Buy Now
We earn a commission if you make a purchase, at no additional cost to you.
01/26/2023 11:38 pm GMT

Finally, we’d recommend Lily once again if you’re looking for a combination of the storm glass and a Galileo thermometer. This particular model features a sturdy cherry-finished wood case that would look great in any office.

The Weather Station Experts participates in Amazon Associates and other affiliate programs and may receive a commission from clicking on links on our site.

About the Author

Ed Oswald

Ed Oswald has nearly two decades of experience in technology and science journalism, and specializes in weather stations and smart home technology. He's written for Digital Trends, PC World, and TechHive. His work has also appeared in the New York Times. When he isn't writing about gadgets, he enjoys chasing severe weather and winter storms.