All About Storm Glass

If you’re curious about storm glass barometers, also known as storm glass weather predictors, you’ve come to the right place. We have comprehensive information about the history of the storm glass, what makes them work and how to use one, so read on.

Storm Glass Barometer

History of the Storm Glass

Admiral FitzRoy, courtesy of Wikimedia Commons

Storm Glasses are amazing devices that have been used by sailors to forecast storms for hundreds of years. The inventor is unknown but the device became popular in the 1860s after being promoted by Admiral Robert FitzRoy, an English officer of the Royal Navy.  FitzRoy achieved lasting fame as the captain of the HMS Beagle during Charles Darwin’s famous voyage.

In 1859, violent storms struck the British Isles. In response, the British Crown distributed storm glasses, then known as “FitzRoy’s storm barometers,” to many small fishing communities around the British Isles for consultation by ships in port before setting sail.

What Is a Storm Glass Barometer?

The Storm Glass barometer is a sealed glass container containing a liquid with crystals that change based on the weather conditions. It can predict sunny weather, cloudy weather, thunderstorms, and even blizzards.  The premise of the functioning of the storm glass is that temperature and pressure affect solubility, sometimes resulting in clear liquid; other times causing precipitants to form. The functioning of this type of storm glass is not fully understood.

How to Use a Storm Glass Barometer

In recent years storm glass barometers have become popular gifts for the home and office. Storm glasses come in all shapes and sizes, but the most common one is the teardrop shape.

Once you receive your storm glass make sure to allow 1-2 weeks for the it to acclimate to your environment.  Do not place the storm glass under direct sunlight or a heating vent as heat can make the glass break.  Make sure to keep the storm glass away from children or pets.

With the storm glass barometer properly placed, crystals will grow in response to the coming weather. The stronger the coming weather, the longer the delay will be between the crystals forming and the weather appearing. The average length of this delay is around two days.  To see an immediate change try placing the storm glass in the freezer for 10 minutes.

Initially, it may be easier just to see what grows and then remember the weather that follows. When these crystals appear again, you will have some idea of the type of weather approaching.

Do Storm Glasses Really Predict the Weather?

Admiral FitzRoy carefully documented how the storm glass barometer can predict the weather:

  • If the liquid in the glass is clear, the weather will be bright and clear.
  • If the liquid is cloudy, the weather will be cloudy as well, perhaps with precipitation.
  • If there are small dots in the liquid, humid or foggy weather can be expected.
  • A cloudy glass with small stars indicates thunderstorms.
  • If the liquid contains small stars on sunny winter days, then snow is coming.
  • If there are large flakes throughout the liquid, it will be overcast in temperate seasons or snowy in the winter.
  • If there are crystals at the bottom, this indicates frost.
  • If there are threads near the top, it will be windy.

Modern storm glasses may not be able to predict the weather quite as precisely as Admiral FitzRoy once claimed, but they can be fun items to have around your home or office.