The Met Office. www.meto.gov.uk
Whether you're an amateur weather watcher or a serious student of geography, the Met Office serves as a great starting point for exploring the vast volume of information provided on the Internet by weather-watchers around the world.
The Meteorological Office, the Government's official forecasting agency, has a Web site that combines information about its own function and history (founded 1854) with a huge number of links showing how the current weather is being monitored.
Along with providing daily updated forecasts, you can find explanations of how forecasts are produced, how weather patterns are observed and how data about the climate is analysed.
From the Met Office site you can follow links to other national weather agency web sites around the world, from Australia to Zambia, giving you an instant global overview of today's weather.