Starting Your Own Weather Station
this special MOO report, we will guide you through the steps
of setting up your own weather station. First of all
you will need to pick a suitable site. The Met Offices around
the world have internationally agreed the following criteria:
1. Over Short Grass
The temperature close to the ground depends on what the surface cover is.
Different surfaces have different properties; readings obtained on different
surfaces are not compatible. It was hence internationally agreed that Met
Stations should be positioned over short grass. This is easy enough if you
live in a temperate climate; but less easy if you don't!
2. Well Away From Trees
Trees can shade a site and change its meteorological characteristics and so
locate your site well away from them.
3. Open Site
True temperatures and wind movement can only be calculated in the site in
open. The ideal radius is 130m. Airfields are hence preferable and this is why
many official Met Stations are located at them (for instance, Bournemouth
International Airport). It is very difficult to find a suitable site and so
this particular criterium is often neglected.
4. Flat Land
Flat land is required so that any unwanted readings can be eliminated. The
most common of these is when cold air gathers in a hollow.
In reality it is very difficult
to stick to these strict guidelines. The BSMO weather station breaks the rules
on two counts, as it is in the middle of a town. Don't be too worried if you
can't find an appropriate site - your readings are never likely to be used in
complex scientific research!
OK, now you've found your site,
what else do you need? A space for your equipment is necessary. If you can get
your hands on a Stevenson Screen, that's an excellent bonus. Otherwise, use a
wooden box which is well ventilated and not directly exposed to the Sun. Met
Office guidelines say that the box should be painted white. The box should be
1.3m above ground level to compensate for action layer readings.
What do you need at your weather
station? Here is a list recommended by BSMO:
Good luck and let us know how
you get on! If you find it difficult to get hold of any equipment please
and we will try to advise you.
- THERMOMETERS. These should
record maximum, minimum and current temperatures. If you can a single
thermometer that records all three - so much the better! You also need web
bulb and dry bulb thermometers for calculating humidity.
- HYDROMETRIC TABLES.
Essential for calculating humidity.
- BAROMETER. Used to record
- ANEMOMETER. Can be used to
calculate wind speed and direction. If you can't get an anemometer, then
use a Beaufort Scale chart and a weather vane.
- RAIN GAUGE.