Predicting weather is not an easy task – something you certainly know if you already tried doing so in Weather Challenge. But how is weather actually predicted? What kind of weather forecasting instruments are used to do so? What are the different types of weather instruments and what are they used for?

In this article we’ll present you 5 most common weather instruments.

5 weather instruments

Thermometer

One of the most popular weather measuring instrument. The thermometer is used measuring the temperature. Most popular unit of temperature is Celcius, however United States uses Fahrenheit. The third most popular scale is Kelvin.

Two parts of thermometer are needed to accurately read the temperature: the sensor and the scale. The sensor is in most cases some sort of gas, liquid or solid, which changes its physical form due to the changes in temperature (e.g. expanding or decreasing its volume). It reactions indicate changes in the environment. The other part, the scale, makes it easy to convert those change into value (e.g. numerical scale visible on the glass thermometer).

Anemometer

Another popular instrument used to measure weather is anemometer. It is used to measure direction and wind speed. Although it was changing its shape over time, the first known anemometer was created by Leon Battista Alberti in 1450.

There are two main types of anemometers: the three-cup anemometer and the vane anemometer. Three-cup anemometers which are primarily used for determining wind speed (often used in ventilation systems and flight tests), as the wind moves the cups, allowing the precise measurement of its strength. Meanwhile, vane anemometers have propellers and tails used to determine both wind speed and its direction.

Barometer

To predict weather meteorologists use a barometer, which allows us to measure air pressure. The measures are provided in millibars. It’s extremely useful for forecasting, as changes in pressure can indicate the change of weather. High and rising pressure means that the weather will be sunny and the sky clear while falling pressure can mean that the rain is approaching.

There are two people who can be accounted for the creation of the first barometer ever – an Italian physicist Evangelista Torricelli and Gasparo Berti, an Italian astronomer. However, the barometer built by Berti, even if earlier, was an unintentional discovery.

Weather Balloon

Weather balloons are simply balloons used in order to transport instruments into the atmosphere. Typically made out of latex, the balloons are filled with helium or hydrogen in order to carry the measuring equipment into the upper air. This type of balloons needs to be lightweight (they weight only about 200 grams!) and thus are very delicate. Because of this, they cannot be touched without protective gear, as any, even the smallest damage can cause the burst when the balloon is in the atmosphere.

They are launched at over 500 locations worldwide twice per day and typically reach heights of 20-30 km before bursting, returning the probe with measuring equipment to the ground.

Stevenson screen

You’ve probably seen it many times – small little boxes surrounded by meteorological equipment. So what are they? Stevenson screen is a box used to store meteorological equipment which can be affected by direct sun radiation, altering the measurements. Those boxes are typically painted white to avoid sunlight absorption and allows free passage of the air to accurately measure temperature and humidity.

Stevenson screen was invented by Thomas Stevenson in 1864. The World Meteorological Organization recommends this design as optimal for measuring weather.