That's the way it goes I'm afraid - we have perhaps not chosen the pastime best suited to the British climate!
Actually, apart from the persistent poor vis for the last couple of months this year has been a lot better than the same period last year, in the south east at least.
You could try booking lessons on twice as many days as you can actually afford, on the assumption that half will be cancelled!
Anyway, welcome to the club - it'll all be worth it in the end.