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
To obtain records of the timing and intensity of rainfall, one or more recording raingauges are often sited alongside the manual raingauge. The record from the manual gauge should be taken as the standard period total and sub-daily records (hourly totals, for instance) taken from the recording gauge adjusted to agree with the daily total taken from the manual gauge. The use of standalone recording gauges is not recommended when accurate or comparable rainfall totals are required.
Most air temperature measurements are now made using resistance temperature devices (RTDs), which are steadily replacing liquid-in-glass thermometers. The main types of sensor in use today are the platinum resistance thermometer and the thermistor. The former is more accurate and more repeatable, but more expensive. Both can be made very small and thus highly responsive.
To measure grass temperatures, a spirit-based minimum thermometer or an automatic weather station (AWS) or dedicated logger with inputs for a trailing-lead electrical sensor (thermistor or platinum resistance thermometer) is required. Entry-level and budget AWSs generally do not include suitable additional sensors or ‘spare’ sensor ports. A sensitive yet robust sensor is required to measure grass minimum temperatures, as it will be exposed to all extremes of weather.
A once-daily ‘morning observation’ is the best time to read/reset any manual instruments in use, as well as perform visual checks on the operation of the sensors for an automatic weather station AWS, particularly raingauge funnels which are likely to become blocked if left unchecked. A manual observation also provides a convenient opportunity to note current weather details such as the amount and types of cloud, the surface visibility, present weather, the occurrence of lying snow, and so on.
To avoid the significant vertical temperature gradients near the Earth’s surface, thermometer/s to measure air temperature should be exposed at 1.2–2 m above ground level. In the UK and Ireland, the standard height is 1.25 m above ground; in the United States, between 4 and 6 feet.