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
Grass and earth temperatures are the most commonly observed temperature measurements, after air temperature. The lowest temperatures on a clear night will be recorded at or close to ground level. Where the surface is covered by short grass, the lowest temperatures are attained just above the tips of the grass blades. The so-called ‘grass minimum temperature’ (or ‘grass min’) is measured using a thermometer or electrical sensor freely exposed in this position. A ‘ground frost’ occurs when the grass minimum falls below 0°C.
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.
Some form of thermometer screen is essential to provide protection from direct sunshine, infrared radiation from Earth and sky, and from precipitation. The main screen types – louvred (Stevenson screen, Cotton Region Shelter), AWS radiation screens and aspirated screens – are covered in some detail in The Weather Observer's Handbook, because the thermometer housing (or lack of it) is likely to have the largest impact upon the observed temperature. Almost any form of radiation shelter will provide better results than a bare sensor. If the AWS model chosen does not include an effective radiation screen, allow budget to purchase a suitable third-party one and use that.
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.
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.