Hi ,
my son did the ppl and night a couple of years ago in august, he did say that thunder storms in the afternoon stopped progess a few times. also the point made earlier about the written exams being done before you go out is important, my boy did it all in three weeks and said it was not so much fun as a "character building experience". he was adamant that having the writtens done before you go would change the whole experience.
good luck
MOREOIL