Here is another very good reason to bin the UK and go and learn to fly somewhere like California. The examiner may 'test' you on your decision to fly or not, I know a bloke who failed before they got airborne as he got the weather info wrong.
(I cannot believe that if the weather is bad you may be required to stump up for the examiners expenses??? What, are they volunteers,a charity, or do they get paid??....is this another case off rip-off Britain?)