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
Earth temperatures are most frequently measured at depths of 5, 10, 20, 30, 50 and 100 cm below ground level. Measurements at 30 cm or deeper are normally made under a grass surface, while the shallower depths are measured under a bare soil plot. Both should remain fully exposed to sunshine, wind and rainfall.
Where accurate air pressure records are required, the observed barometer reading needs to be adjusted to a standard level, usually mean sea level (MSL), because air pressure decreases rapidly with altitude. A variety of approaches exist to correct or ‘set’ a barometer to mean sea level: four are described in The Weather Observer's Handbook The choice of method depends upon accuracy sought (and the accuracy of the sensor) and height above sea level. Downloadable Excel spreadsheets are available on this site to simplify the production of site-specific sea level correction tables where desired.
Traditional louvred screens can accommodate both traditional liquid-in-glass thermometers and small electronic sensors, but small AWS radiation shields can be used only with electronic sensors. Aspirated units currently provide the best estimate of true air temperature (they are highly responsive and largely free of influence from the screen itself), but they provide a slightly different temperature record from other standard methods. Next-generation climate monitoring networks are increasingly using aspirated methods of measuring air temperature.
Raingauges should be exposed with the rim at the national standard height above ground – in the UK and Ireland, this is 30 cm; in the United States, between 3 and 4 feet (90 to 120 cm). Most countries define a ‘standard rim height’ as between 50 cm and 150 cm above ground. Take care to set the gauge rim level, and to maintain it accurately so.
Weather station specifications within The Weather Observer's Handbook are suggested within four very loose ‘user profiles’ – Starter, Hobbyist, Amateur and Professional – intended as a pragmatic starting point to what is practical and affordable within various budget and site restraints. As an example, with a limited budget it is probably better to concentrate on air temperature and rainfall observations: wind speed and direction (for instance) are more expensive to measure, and the site requirements are more complex. These and other elements can probably follow at a later stage as budgets (and perhaps an improved site) allow.