Here is something that I charted (from NASA sunspot data) when trying to analyse floods and droughts here in Oz. Notice the repetitive 11 year cycle. The droughts and floods correlate nicely btw.
* doghunter *
It is left as an exercise to try and figure out HOW the sunspot cycle affects earths weather.
The correlation is well studied and very clear.
The actual mechanism is still not actually identified.