Water barometers are a beautiful and functional piece of home decor. There is an old-fashioned elegance to reading the weather this way, and it's amazing how accurate such a simple device can be. Luckily, it's also simple to read. To determine the likely weather, you have only to see how high or low the water is in the glass.
Look at the water in the spout of the barometer. If the water holds steady around the middle of the spout, you'll have good weather. The water should never dip below this middle amount, so it's the default position of the water.
Check to see if the water creeps up the spout. This means a pressure system will be in your area in about eight to 12 hours. Pressure systems can bring storms.
See if the water springs quickly up the spout; if so, a storm is likely coming. Make any arrangements necessary for inclement weather.
See if the water is dripping from the spout; if so, bad weather is coming very quickly. It will probably be there within a few hours. Luckily most water barometers have a drip guard for when this occurs.
Watch to see if the water begins dropping down the spout during a storm; if so, the weather is going to begin clearing up.