any time after the water hits 55 degress is prime topwater fishing (one of the articles on this site suggest its the first bait you should throw). basically, once the water hits 55-60 deg, bass start spawning and obviously get very protective over their nests. a lot of people over look top water presentations during the spawn. when the fish are spawning (especially shallow), top water baits like frogs, buzzbaits, and spooks make too much commotion for the bass to stand and they end up destroying it. bass not only have to worry about horizontal attacks from nest robbers but vertically too. i've seen a lot of bass give the cold shoulder to lizards and rodents but once they see a spook walk over head, they turn their nose up, prime their tail and explode skyward. pretty fun to watch.