The weather in GA flying is usually less than perfect, it's always different, everyday. The key is not to worry about it. Easier said than done huh?
I did my PPL 6 months ago and the weather was less than perfect, in fact due to the wind strength I nearly cancelled it myself! The examiner however, given these conditions, used his discretion. I didn't pass the test easily and remember thinking around the end of the nav phase that I'd call it a day and RTB. Glad I didn't, the rest went well, I learned some new things from the examiner; after all it's a different persons perspective and attitude to flying.
All you can do now is prepare well, sleep well, work hard to correct
anything that goes awry tomorrow, and expect to learn something new even though it's a 'flight test'.
Good luck although you won't need it and be sure to let us know how you get on
