How to choose the right spot for your weather station and assess it using the WMO international standard: the siting guide for MeteoEdu partner schools in Romania, Germany and France.
📋 The detailed participation criteria are being finalised; the siting guide below already applies.MeteoEdu is part of the Erasmus+ EASE project, with partner schools in France, Germany and Romania.
A weather station only measures correctly if it is sited correctly. If the temperature sensor sits next to a wall that heats up in the sun, or above asphalt, it will read 1–5 °C higher than the real air temperature.
In the MeteoEdu network we compare data between schools in Romania, Germany and France, so all stations must be sited by the same rules; otherwise the comparison is meaningless.
The World Meteorological Organization (WMO) defines an international standard in which every measuring site receives a class from 1 to 5, separately for each measured quantity (temperature, wind, radiation).
Our station is an integrated station: temperature, humidity, wind, rain and UV are all in a single body. We cannot satisfy every sensor's ideal height at once (the thermometer wants ~2 m, the anemometer wants 10 m), so we choose one mounting compromise:
The table below shows which class you get depending on the distance to these obstacles:
| Class | Minimum distance to buildings / asphalt / concrete / parking | Vegetation and terrain | Added error |
|---|---|---|---|
| 1 | over 100 m | flat ground, grass under 10 cm | reference |
| 2 | over 30 m | flat ground, grass under 10 cm | very small |
| 3 | over 10 m; no shade when the sun is higher than 7° | grass under 25 cm | up to 1 °C |
| 4 | buildings/concrete close by: under 50% of the surface within 10 m and under 30% within 3 m | any | up to 2 °C |
| 5 | does not even meet class 4 requirements (sensor against a wall, under eaves, etc.) | any | up to 5 °C |
On a pole at about 2 m. Students can see the station and understand its components (even if they don't touch it), and the temperature stays correct, measured above grass.
At roof height. Advantage: wind comes out better (the anemometer is higher and freer). Disadvantages: students no longer see it up close, and the roof surface (bitumen, tiles, sheet metal) heats up strongly in the sun and can distort the temperature, so place the station as far as possible from the hot surface and note this in the classification.
Wind. Ideally an anemometer would be mounted at 10 m, away from obstacles. On an integrated station mounted in the yard (~2 m) that is impossible, so wind will almost certainly be class 4S or 5S. That is perfectly normal and honest for a school station. If the station is on the school roof, wind comes out better (higher and freer). In both cases, mount the station as freely as possible and record the height.
Solar radiation. The station has a UV / solar radiation sensor. What matters is that the spot is not shaded by buildings or trees in the middle of the day and has nothing above it. For class 1, no shade when the sun is higher than 5° above the horizon; for class 3, higher than 10°.
Go out into the yard with a phone and a tape measure (or counted steps) and answer:
It stays in the school's file, together with photos of the site.
| What we record | Your answer |
|---|---|
| School name | |
| Town / county / country | |
| Name of the operator (student) and of the teacher in charge | |
| Date of the observation | |
| Mounting place (schoolyard / school roof) | |
| Height of the station body above ground (target: 1.25–2 m) | |
| Distance to the nearest building / wall (m) | |
| Distance to the nearest concrete / asphalt / parking surface (m) | |
| Distance to the nearest water (pond, well, pool) (m) | |
| Ground type under the station (grass / concrete / gravel / other) | |
| Does the spot get shade from buildings/trees at noon? (Yes / No) | |
| Is there open sky above the station? (Yes / No) | |
| Can the station be fixed securely, safe from theft and knocks? (Yes / No) | |
| Can a 3×1.5 mm² power cable be run safely? (Yes / No) | |
| Is there stable WiFi / internet signal at the station site? (Yes / No) |
Classification result:
| Parameter | Class obtained (1–5) | S flag? (Yes/No) |
|---|---|---|
| Temperature and humidity | ||
| Wind | ||
| Solar radiation / UV |
The environment changes: a tree grows, an annex is built, a path gets asphalted. That is why the WMO recommends a visual check every year and a full reclassification at least once every five years.
Reference standard: ISO 19289:2014 / WMO-No. 8, Annex 1.B: Siting Classifications for Surface Observing Stations on Land.