Home weather stations

If you are interested in weather web-cameras, you will certainly have a parallel interest in weather observation. This section gives a very brief introduction to home weather stations.

Desktop weather stations

Traditionally, weather data has been recorded with instruments placed in a standard white wooden housing called a Stevenson Screen. Inside the Stevenson Screen, basic instrumentation includes a maximum and minimum thermometer, a hygrometer and a barometer. There may also be instruments for recording wind velocity and direction. A meteorologist manually records the instrumentation in the Weather Log Book, often at midday, every day, regardless of the weather! Although a Stevenson Screen is meant to be mounted 1.2 meters above open ground, Stevenson Screen's are frequently found atop buildings in cities. In principle, all readings taken at this weather station are consistent with this environment only; and with consistent readings over many years, the local climate can be established.
With the advent of the desktop weather station, the home meteorologist has no need for a Stevenson's Screen, or even the need to go outside to take measurements. From a simple desktop clock with a weather predictor, to a sophisticated system with a roof mounting weather sensor array and computer interface, the armchair meteorologist has many choices.

Wired weather

Some desktop weather stations have the ability to download data held in their internal memories to a computer over a USB lead. This is done either live, viewing the conditions in real-time or, as a bulk dataset once every one or two weeks. It is important to understand how much data, or sample frames a base station can hold. Some budget weather stations can only hold a couple of days worth of data whilst some others will not store any data at all; they can only show the now conditions. Endeavour to download the user manual from the manufacturer's web site to find out what a potential weather station can really do.

Many desktop weather stations with computer connectivity, ship with software that generates graphical displays of weather conditions; temperature over the last day, precipitation over the last week and maximum wind speed for the month, for example. Archived data can then be used to observe weather trends.

Custom third-party weather monitoring software also exists which claims compatibility to certain brands of weather station. Third-party software may offer extra features like data uploading to a custom web page, data capture from other weather resources and, sending email alerts when extreme conditions are detected.

The outside sensor array is connected to the desktop weather station either by cable or, commonly, via a wireless radio link. The remote sensor array will often need an independent power supply, which is usually batteries. Although some pricier models are installed with solar panels. Batteries have an aversion to cold, hot and wet conditions, which is exactly where they are deployed. Extra sealing may be required for all electrical parts, especially in corrosive atmospheres. For consistent readings, the senor array should be sited away from obstructions such as trees and walls. However, they must be also accessible for easy maintenance. Mounting on a pole which is hinged at the base, will avoid proving gravity when slipping off the roof! The sensor mast may also be the ideal place to mount the weather camera in it's external weather-proof housing.

A desktop weather station connects to a home computer. Software on the computer sends weather data across the internet. The weather station's home page shows both weather data and the view from the weather web-camera. By signing up to a community weather service, the local weather data and webcam image can be shared with the wider world!

Touching the sky

Like their mechanical counterparts, electronic weather stations sample and store weather conditions such as temperature, wind speed and direction, humidity and precipitation. The more sophisticated the model, the more sensors.

The remote sensor array for an electronic weather station should be located, where practical, high and clear of local obstructions. The wind vane and anemometer should be positioned around three meters from ground level so they will turn freely in the slightest breeze. In practice, most home weather arrays are compromised by overshadowing trees and sheltering buildings, which create a micro climate.
A weather station to Met Office standards requires a lot of open space for the sensors; usually an area of mown grass. In an urban setting, the open space is often the flat roof of an office building.

The accuracy of a desktop system depends on unknowns such as design, manufacturing and the local setting. When starting out, discover any inconsistencies between trusted values and those produced by the new system. For example, when compared to a standard thermometer, a system may over or under read by a few degrees centigrade. Pressure may be out by a millibar or two. Wind speed may be more indicative than definitive. Precipitation recorders can have a tolerance of ten percent, provided they are not frozen solid! Fully calibrated systems are very expensive.


			In summary Home weather stations are really cool toys. Some devices can update a web page. Mount sensors away from obstructions. Don't expect readings to be decimal point accurate. Are a great addition to a weather web-camera.