Tire pressures sometimes seem like a bit of a dark art, which is something not helped by all motorcycle and tire manufacturers. For a few years now manufacturers have been quoting factory pressures at about 36psi front and 42psi rear. Obviously if you jumped on track with those, you'd probably jump off it pretty quickly too.
Although tires like the new Michelin Power One can run as low as 22psi in the rear on track, as a general rule in the dry season for road riding, we tend to recommend about 32psi front and 35psi rear. What's the deal with the raining season then? Should we go up or down to compensate for less ambient heat? Well the simple answer is: neither. Obviously a manufacturer will still quote the 36/42 liability protecting nonsense at you, but if you don't ever ride two up, or use your motorcycle for robberies, then the 32 or 33 on the front with 35 or 36psi in the rear should see you good all year round. Obviously if you intend on attending trackdays then you'll need to come down a few psi to prevent your tires from overheating.