The BBC provides the weather forecast for the next 5 days or 24 hours.

RainToday shows the areas of rain (and intensity) for the last 2 hours which is a great aid in determining the likely rainfall in the next hour or two. This site uses the Met Office rainfall radar images (one every 15 minutes) and is extremely accurate and detailed once you have entered your post code. A useful tool if you are about to start travelling or commence an outdoor activity.