Siting Your Weather Station

When you need to monitor weather at your research project, or industrial site, a local weather station of your own is usually the best solution. Not surprisingly, there is often confusion about
the best place to install it. Can it be mounted on a nearby building? What height should it be? And so on.
Essentially, there are two main factors that Environdata (Australia) suggest determine where to site a weather station. These are; firstly your intended application, and secondly the impact of the surrounding environment on the relevance of your data. A weather station records the
weather exactly at the point it is located. In some applications, we wish to infer that those readings are valid for a radius of 1 to 2 kilometres. This is called a ‘microclimate’ application, and measures the weather including the effects of the local terrain, including the topography, trees, fences, buildings etc. In other situations, we would like to infer that the readings are valid for up to 25 kilometres. This is called a ‘Meso-scale’ application and the aim is to measure the weather independently of any immediate effects or local terrain.
Microclimate monitoring is primarily used where the specific conditions and effects of the local environment are of importance. This includes some research trials and many industrial sites and environmental licensing or control situations. The station should be located as close as possible to the area under investigation. It is important to choose a site that is clear of trees or overhangs. Nearby trees or buildings should be no higher than one quarter of their distance away. Often for microclimate applications, you might consider the roof of a building on your site as an ideal place to locate a weather station. Usually, a roof is a good choice as long as the previous guidelines are followed and the wind sensors are mounted at least 2 metres above the roofline to
minimise the eddies caused by the roof edge. Meso-scale siting requirements are more stringent and to achieve optimum results, the following guidelines should be considered. This includes a 10-metre mast for wind speed and direction sensors and radiation sensors, with trees or other obstacles no higher than one tenth of their distance away. The location should be flat and level. These requirements may be difficult to achieve in practice, and therefore some compromise is
usually required.
Mounting wind sensors at 10 metres ensures that the effect of the local terrain is minimised, and effectively measures the ‘area’ wind rather than just the ‘local’ wind. Typically, this is used for odour, dust and air pollution monitoring, to satisfy Australian EPA licence conditions, and for research trials where localised meso scale data is required.