My rain gear is always packed on the bike. Living in Central Fla thats just the way it is. 30% chance is 70% you miss. The way the weather man has described it here lately is that 30% of viewing area may get wet. Here lately ther can not be a cloud in the sky and I take bike down to Wally World for something and I'll get rained on before I get home. And its a 5 min drive.
A trip around town here if it looks bad I probably wont ride. If its a big trip say vacation I would prefer not to ride in rain, but OH well. Just be safe, if its a down pour and you cant see the road or your ridding on a road you should have a canoe instead, stop awhile.