Anemometer

An anemometer is a tool that measures how fast the wind is blowing. Think of it as a speedometer, but for the air around you instead of a car. The most common type you’ll see has three or four small cups attached to horizontal arms. These arms spin around a central pole. When the wind blows, it pushes the cups, making them spin. The faster the wind blows, the faster the cups spin. The device counts how many times the cups spin in a certain amount of time and uses that to calculate the wind speed.

People use anemometers to get accurate information about wind conditions. This is important for many activities and professions. For example, pilots and air traffic controllers need to know wind speeds to keep flights safe during takeoff and landing. Sailors and boaters use them to decide whether it’s safe to go out on the water or to adjust their sails. Farmers might check wind speed before spraying crops to make sure the wind doesn’t carry chemicals where they aren’t wanted. Even construction workers use them to ensure it’s safe to operate cranes on windy days.

You don’t have to be a professional to come across anemometers. Many home weather stations include a small anemometer, often placed on a roof or in a backyard, to give homeowners real-time wind data. Some people use handheld versions when they go hiking or camping to check conditions, especially in mountainous areas where weather can change quickly. You might also see them built into smartphone apps or small, portable gadgets that outdoor enthusiasts carry. Even if you don’t own one, you’ve likely seen them on top of buildings or at marinas, quietly spinning away to help keep people informed and safe.