Unless there is a huge settled mass of high pressure over the country the weather forecasters have little success with their forecasts. I have been looking at their forecasts for two to five days out in some detail for the past eighteen months or so. For day three, the forecast changed on no less than 48% of the occasions before that day became day two. For day five it changed 87% of the time before day five became day two. (By "changed" I mean from rain to sun, sun to cloud, etc., not simply a change of forecast temperature). So theres almost 50% chance that a three day forecast will be revised and a 90% chance that a five day forecast will be revised. And that's without even bothering to compare the forecast with the actual, which is another story.
Anybody who takes any notice of �long range� forecasts and makes plans or spends money dependant on them should not be surprised if their plans are thrown into disarray. As for the costs involved, it is often less expensive to get a cheap and cheerful holiday in Spain or Greece for a fortnight than it is to spend a week in a dreary English seaside hotel.
Of course, you destroy the atmosphere by flying for a couple of hours each way and threaten the future of mankind (or so I'm led to believe) but at least you will have a reasonable chance of being able to step outside when you are on holiday.