I can't give you a water temp to go by (maybe somebody else would know) but I just keep throwing top water baits till my bites become few and far between. I'm guessing that'd be when the water temp gets in the low 50s??? Then I slow down and throw a soft plastic jerk bait (caffiene shad is my favorite but flukes and Zulus work really well too). Then by late fall early winter I'm back to tube jigs (my all time favorite bait).

I also thought I should mention fall is a great time to pull out the bigger lures in your tackle box. Not so much because the bass want a big meal but rather because the bigger bass are going to be just as active as the rest of them trying to fill up before winter comes. And you know how the saying goes... Big bait=big fish!