Scottish weather is totally unpredictable. Because we are close to the sea, a large continent, the arctic and the warm air from the gulf stream, there are many conflicting influences. Weather patterns change immensely in time periods of a few hours. It can also be very dangerous. We have often have a combination of strong winds with rain show and hail. This means that temperatures which would be completely unthreatening in other conditions lead to hypothermia. Many people have come here equipped for small hills and easy conditions (4000 feet does not sound impressive to people used to 4000 meters) and got into serious problems. End of dire warnings.
Understanding the climate in Scotland is crucial to enjoying visits to the hills. First read a general introduction. Then try to find out more details on weather today.. Finally, if the are relevant to you, try out one of the services providing information to climbers.
After this you may want to go hunting for more general info.. Difficult indeed..
The Telegraph is a bit of a pain as you have to register for it so I can't give you a direct reference. You'll have to find the weather on your own.
See also our page on conditions generally (should include such things as midges which we can happily avoid mentioning here).
Just remember that the weather can change at a moments notice, you would
also be well advised to 'get the telly on' and see what John Kettely
or the like have to say on the matter.
M.J.Steer@Sheffield.AC.UK (Matt Steer)