This is not only one of the best weather forcasting websites on the internet (as it's linked through the Met Office), but you can also find out about the RAC/Weathercall traffic information service number. If you haven't already discovered it, put it into your mobile now. What you get is a quick and easy to use service telling you about all the problems on the motorways, so you can avoid getting stuck before you set out.
Although you can never be sure of the weather forecast (putting it mildly) and definitely don’t believe what you read anywhere on this website you can at least get some idea of what is expected for the next ten days, hour by hour if you want and for anywhere in the World. If you want overseas weather just type in the country name and you’ll get a list of cities. It may not always get it right in terms of day by day but it’s usually pretty good about likely temperatures.