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
Instrumental readings are of course vital in making observations of the weather, but for a complete picture non-instrumental and ‘narrative’ weather observations are equally important, especially for the analysis of severe weather events.
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.
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.
It is advisable to check and test all sensor / datalogger / software and communications thoroughly, over a period of at least a few days, before permanent hardware installation or embarking on any long-term data collection.
Choosing a weather station can be complex and a number of important factors may not be immediately obvious to the first-time purchaser. Deciding a few months down the line that the unit purchased is unsuitable and difficult to use (or simply does not do what you want it to) is likely to prove an expensive mistake, as very few entry-level and budget systems can be upgraded or expanded.