La Locherie Weather Station

Conditions at La Locherie are recorded by a personal weather station manufactured by Fine Offset Electronics, but badged and sold as an N96GY by Maplins. Sensors positioned 25 metres from the house measure temperature; outside humidity; barometric pressure; rainfall volume; wind speed and wind direction and transmit the data to an indoor base station via a wireless network.

In addition, the base station measures indoor temperature and humidity, displays the data and provides a fairly accurate forecast. However, the 12-hour forecast we display is calculated through a software program called Cumulus, developed by Steve Loft. This uses a mathematical formula called an algorithm, which was developed by barometer makers and is reckoned to be around 90 per cent accurate, especially when read at 9 am.

Cumulus is more sophisticated and elegant than the program provided with the station and in addition to the measurements taken by the station, it calculates the average temperature; wind chill, heat index; dewpoint; temperature trend; cloud base; rainfall rate; 10-minute average wind speed; 10-minute average wind direction; wind run and pressure trend. (For an explanation of these meteorological terms see the Cumulus Wiki). We have developed the way the data is displayed in line with our own requirements and preferences.

Our sensors are located above grass: the rainfall gauge at 6ft, barometric pressure and temperature sensors at 7ft and the wind sensors at 8ft. Data from the sensors is transmitted every 48 seconds and the meteorological day used by the station ends at midnight, local time. The daily data collected has been stored since records began on 19th December 2009 and is presented via a series of historical graphs, showing information for the last 1, 3, 6 and 12 months.