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 new book The Weather Observer’s Handbook (Cambridge University Press, 2012), 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
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.
The traditional method of measuring humidity is by using a pair of matched mercury-in-glass thermometers, known individually as dry-bulb and wet-bulb thermometers and in combination as a dry- and wet-bulb psychrometer. The wet-bulb is a thermometer whose bulb is kept permanently wet using a thin close-fitting cotton cap or sleeve. The wet-bulb is cooled by evaporation, and the difference in temperature between dry-bulb and wet-bulb thermometers is a measure of the humidity of the air. Using tables, an online calculator or formulae, the relative humidity (or any of the other humidity measures) can be quickly and easily determined from simultaneous readings of the two thermometers.
Weather knows no boundaries. The inherent interest in taking weather observations are greatly enhanced by exchanging and comparing observations with others locally, nationally or internationally.
Wind is a vector quantity – it has both direction and speed. Wind direction refers to where the wind is coming from. A wind vane needs to be accurately aligned to true north, which is slightly different to the magnetic north shown by a magnetic compass.
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.