The Met Office's David Dehenauw explains: "We’ve been brooding on this project for some time. There are thirty fixed weather stations that dispatch information on an hourly basis. We would like to collect information at a very local level too. That's why we are co-operating with Bpost, a business that travels everywhere."
Thirty postal vans will measure the temperature and use sensors to gather information on road conditions, e.g. is there snow? Microphones under the bonnet (or hood) will tell when there is hail. Windscreen wipers and fog lamps too will provide information.
The Met Office will enter all this information into sophisticated weather computers to allow weathermen and women to follow the situation. In time, in ten years or so, the Met Office hopes to provide reliable information tailored to each municipality, but postmen won't have to do any extra work!