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
By convention, 24 hour minimum temperatures read at the morning observation are entered to the day on which they were read, whereas 24 hour maximum temperature and total rainfall are entered to the day prior to the observation (they are said to be ‘thrown back’).
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.
Dry- and wet-bulb thermometers can easily be replicated using electrical sensors, although small capacitative humidity sensors have largely replaced the traditional dry- and wet-bulb psychrometer. Modern sensors are small, economical on power, more reliable at temperatures below freezing and datalogger-friendly.
The preferred resolution of a recording raingauge is 0.1 or 0.2 mm; 1 mm tipping-bucket raingauges are too coarse for accurate measurements of small daily amounts. Recording raingauges should be logged at 1 minute or 5 minute resolution (higher frequencies are possible using an event-based logger). They should be regularly inspected for funnel blockage or any obstruction to the operating mechanism, which will result in the complete loss of useful record if not quickly corrected.
Recording raingauges can be easily and accurately calibrated by passing a known volume of water through the gauge, and comparing with the indicated measurement. ‘Out of the box’ errors for some AWS tipping-bucket raingauges of this type can exceed 20 per cent, so this is a vital test for all new instruments at first installation. Recording raingauges should not be adjusted merely to attempt exact agreement, or near-agreement, with a standard raingauge, because instrumental and exposure differences inevitably lead to slight variations in the amount of rainfall recorded.