Wind Measurements

The wind brings us different sorts of weather. It also affects our lives when it blows strongly, and even when it does not blow. It is an important aspect of the weather for meteorologists.

It is important to take wind readings in a place away from any tall objects such as trees and buildings. These can have the effect of sheltering you from the wind, or speeding up the wind as it goes round the obstacle. Hold the anemometer as far away from yourself as is practical. You will need to be able to read the scale.
See about where to put your weather vane for observing wind direction on the More About Setting up Your Weather Station page.

When you have finished reading about this you may want to find out more on More About Wind Measurements, find out how to put your data to use on the Wind Roses and Wind Direction page or return to Collecting Data. You may also like to have a go at the Wind Direction Quiz.

Wind Measurement

There are two pieces of information that we need about the wind. We need to know its direction and its strength.
Wind is moving air, which is traveling from one place to another. This movement is linked to air pressure, as air moves according to different pressure systems.
The building in the picture is named 'The Temple of the Winds'. See more about this on the Tower of the Winds page.
Hot air balloons have to go wherever the wind blows them

Wind Direction

This is recorded by using the eight points of the compass. We record the direction from which the wind is coming. This is important because different directions will bring different types of weather. For more accuracy the sixteen points of the compass can be used.
A weather vane needs to be high up and not near any buildings so that it is blown on by unobstructed wind.
When you take the wind direction readings you need to watch for several seconds. This is especially the case if it is very windy. The video clip on the right shows how the pointer can move about. Can you hear how windy it was? You need to choose the direction the pointer points to most.
If you record the wind direction you may want to use it to help forecast the weather. Find out more about how to do this on the Wind Roses and Wind Direction page.

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[Sound of wind only]

A Good Weather Vane

It is usual to have a weather vane which points in the direction from which the wind is coming. A good weather vane has a large surface area at the opposite end to its pointer. This makes it point the right way to where the wind is coming from.
It can be good to have a pretty weather vane. Lots of people have shapes on their weather vanes that fit in with their hobbies or things they like. If these are going to work they must still have more of the sail at the end away from the pointer.
Click on the picture of the cathedral to see a larger image and investigate the weather vane.

brimingham cathedral

A Not-so-good Weather Vane

Some people are so keen to make a pretty weather vane that they do not check that it will point in the right direction. If there is more of the shape at the pointer end than the tail end it will point exactly the wrong way!
The beautiful train weather vane on the right has much more of the sail at the pointer end that at the back end. This means it will tell you where the wind is going instead of where it is coming from!

train weather vane design

Wind Strength

This can be measured in kilometres per hour, miles per hour and metres per second (i.e. by measuring the speed of the wind.). It can also be measured by using the Beaufort Scale. The wind meter in the picture can be used to measure the strength of the wind in miles per hour, which can then be converted into Beaufort Scale measurements.

Wind Measuring Devices

This instrument must be held in the middle, with the two holes at the bottom facing into the strongest part of the wind. If there is wind, the white ball in the central column will rise up. The monitor needs to observe the rise and fall of this ball, and make a judgment as to the average reading on the scale. If the wind is gentle the aperture at the top is left uncovered, and the left hand scale is read. If the wind is very strong the top aperture is covered and the right-hand scale is used.

Using ICT

There are many digital devices which can help record the wind direction and strength. The advantage of the device in the photograph is that it can measure current wind strength, average wind strength and gusts.

To see other digital devices look in the ICT page.

The Beaufort Scale

This scale helps people to describe how strong the wind is. There are numbers 0 to 12, with 0 being no wind, and 12 being the strongest. The pictures and descriptions below will help decide how strong the wind is. The scale was the work of Sir Francis Beaufort in 1805. His first descriptions helped sailing ships and had descriptions about the sea. It was later adapted for use on land. It is still used in shipping forecasts.

  0 - Calm. Smoke rise vertically.
(<1 kph)
1 - Light Air. Smoke drifts.
(1 - 5 kph)
2 - Light Breeze. Wind felt on face. (6 - 11 kph)
3 - Gentle Breeze. Leaves move.
(12 -19 kph)
4 - Moderate Breeze. Branches move.
(20-28 kph)
5 - Fresh Breeze - small trees sway. (29 - 38 kph)
6 - Strong Breeze. Wires whistle.
(39 - 49 kph)
7 - Moderate Gale - whole trees sway.
(50 - 61 kph)
8 - Fresh Gale - twigs break off.
(62 - 74 kph)
9 - Strong Gale - slates are blown off.
(75 - 88kph)

10 - Whole Gale - trees uprooted.
(89 - 102 kph)

11 - Storm - widespread damage.

( 103 - 117 kph)
12 - Hurricane - disastrous.
(over 117 kph)