- How to read wind direction?
- What does wind speed show?
- How can you determine the wind direction yourself?
Wind direction
When reading the weather report, we are usually interested in what kind of air temperature is expected, and whether rainfall will occur. But weather reports can also mention wind and its direction. When a northerly wind is blowing, it means the air is moving towards us from the north. Winds blowing from different directions bring different weather. For example, storms are most frequently brought to the Baltic Sea by westerly winds. The northeasterly wind mostly brings cloudless skies and cold air. Warm air reaches Europe with southerly winds.
It is crucial to know the speed and direction of wind if you plan to fly a kite, sail, or ride in a hot air balloon. Wind speed and direction affect the everyday boat connection between the mainland and islands as well as with other countries.
The easiest trick to determine the direction of the wind is as follows: go outdoors, make your finger wet in your mouth, then lift it into the air. We know that the wind accelerates the evaporation of water (laundry dries faster outside). When water evaporates from the surface of the finger, it cools it down. The wind blows from the direction where you feel a coolness on your finger.
- From east to west
- From west to east
Think!
- In addition to the methods mentioned above, what other options can you use to determine the direction of the wind?
- When and why is it important to know the direction of the wind?
Wind speed
It's also useful to know the wind speed. If there is a storm, smaller ships will remain in the harbour, and aircrafts will not be allowed to take off from the airport. A storm can break trees and power lines, lift roofs from houses and sink the ships at sea. Heavy snowfall with strong winds can clog the roads and bury the cars in snow.
The weather report usually indicates how many meters per second (m/s) or kilometres per hour (km/h) the wind is blowing. For example, a wind speed of 5 m/s means that the air travels 5 meters in 1 second. Wind speed can also be estimated by the effects it has on nature.
Wind speed (m/s) |
Wind strength |
What we see on land and at sea |
0 |
Calm |
Smoke rises straight up. The sea is smooth like a mirror. |
3 |
Light breeze |
Tree leaves are shaking. Light waves. |
10 | Strong breeze | Trees bend. Waves are getting bigger. |
20 |
Storm | The tree branches break. The waves are high. |
30 |
Hurricane-force |
Buildings are damaged. The waves are dangerous for ships, the air is full of water splashes. |
Think!
- See the table for the speed at which the wind blows in these pictures.
- When and why is it important to know the wind speed?
I now know that…
Wind direction in weather reports shows which cardinal direction (north, south, east, west) the wind is currently blowing from. Wind direction can be determined by a wind sock or a weather vane. Wind speed measures how many meters the air moves in a second. The strength of the wind can also be estimated based on the effects it has on nature.
