The Great UK Weather Watch (UKWW) took place on Wednesday 17 March 2004 during the third week of MetLinkInternational 2004, the Royal Meteorological Society’s annual online weather project for schools and individuals. All who took part were asked to observe the weather at least twice during the day (every three hours from 09:00 to 18:00 Local Time, if possible) and to enter their observations in the MetLink database. Provision was made for the following observations to be entered in the database: current temperature, maximum temperature, minimum temperature, relative humidity, barometric pressure, wind speed, wind direction, precipitation amount, precipitation type, precipitation intensity, cloud amount and cloud type. A box for comments was also provided.

The project focused upon: + local variations of weather in relation to topography, urban influences, etc; + observations in relation to climatic norms for the time of year; + comparisons of the observations made by Weather Watch participants with those made at official weather stations; + comparisons of the clouds reported by Weather Watch participants with those indicated by satellite images. The project also included a weather forecasting competition.

A report on the project was prepared by the Education Resources Manager of the Royal Meteorological Society, with the assistance of the meteorologists who helped analyse the observations. The report was published online. The project highlighted problems of using electronic meteorological instruments and automatic weather stations and drew attention to the need for attention to be paid to the calibration and correct exposure of instruments.

This paper will consider the aims, objectives, methodology and outcomes of the project.