This site provides useful practical information related to global and national weather observing practices and instruments, including independent equipment reviews.
You will find much of the background in my book The Weather Observer’s Handbook (published by Cambridge University Press), details of which can also be found on this site, together with useful links and downloads.
Author, The Weather Observer’s Handbook
A nation obsessed with the weather? Yes, certainly, but which nation?
Tip of The Day
Current local records can often be augmented and compared with historical records from the national climate archives. In many countries, online access and downloads are free or available at a nominal charge.
A good exposure for one sensor can be the exact opposite for another. For representative wind speed and direction readings, for example, an anemometer mounted on top of a tall mast in a very open expanse is ideal, but this would be a poor exposure for a raingauge owing to wind effects. No single exposure will provide a perfect fit for the requirements of all sensors.
By convention, weather measurements throughout the world are made to a common time standard – Coordinated Universal Time (UTC). For all practical purposes, UTC is identical to Greenwich Mean Time (GMT).
Precipitation measurements are very sensitive to exposure – particularly to the wind – and the choice of site is very important to ensure comparable and consistent records are obtained. Choose an unsheltered (but not too exposed) spot for the raingauge/s – loss of catch through wind effects is the greatest single error in precipitation measurements, particularly in snow. A site on short grass or gravel is preferable. Wherever possible, obstructions (particularly upwind obstructions in the direction of the prevailing rain-bearing winds) should be at least twice their height away from the raingauge. Rooftop sites are particularly vulnerable to wind effects and should be avoided. The site should also be secure, but accessible for maintenance (grass cutting, etc.) as required.
Generally speaking, the best exposure to the wind will be obtained by exposing both anemometer and wind vane in as open a position as possible, as high as possible, commensurate with both safety and accessibility for installation and maintenance. The necessarily elevated exposure will increase the vulnerability of the instruments to extreme weather conditions, particularly snow or ice, lightning and of course high winds. Great care should be taken in installation and cabling to minimize the potential for subsequent weather-related reliability issues.