Not really an answer, but two points I remember:
-) here in Belgium, glider pilots count on an average of 50 flyable days per annum, or so I was told by one of them. Of course gliders are most demanding of all, regarding weather.
-) for PPL/LSA flying, make a distinction between flying circuits and flying over land: more than once I had planned an overland navigation exercise, only to be told by my dear instructor the weather was barely sufficient for some nice circuit training, but leaving the circuit was not a good idea.