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
Making weather measurements, particularly using an automatic weather station (AWS), can quickly generate vast amounts of data and these can become unmanageable without some thought being given to how records are to be kept and used.
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.
Current local records can often be augmented and compared with historical records from the national climate archives. In many countries, online access and downloads are free or available at a nominal charge.
Site metadata statements are important because they provide the essential information for any other user of the records to understand more about the location and characteristics of weather records made at any site, thereby enabling more informed use of the data to be made.
‘Humidity’ refers to the amount of water vapour in the air, a vital component of the weather machine. Various measures are used to quantify the amount of atmospheric water vapour – relative humidity and dew point being the two most commonly used. Knowledge of any two values can derive other humidity parameters. The amount of water vapour that the air can hold varies significantly with temperature – saturated air at 0 °C holds only a quarter of the amount that saturated air at 20 °C can hold.