Crappie will spawn into Memorial Day weekend in Smithville Lake. I've caught them on the spawning beds that late. Our cold spring has delayed the start of the spawn, but we have plenty of time for it to get rolling good. The longer water temps remain below 60 degrees, the shorter the spawn may be. When water temps get right it may be a mad rush to the banks. I had 59 degree water temp in a 17 acre lake north of Platte City today. I suspect by Monday the spawn will be in full swing if it not before. Spawning is usually triggered by length of day, but temperature does play a part. Last year when it warmed up so fast some of the fish moved up early to spawn but most hit the banks right on time or a week or so early. Water temperature rarely affects things by more than 2 weeks either way. Although the temps in early April this year were so extreme, we never saw walleye go to the dam at Longview Lake in any numbers. Just a few here and there. I expect the crappie spawn to peak the next 2 weeks, so hit it hard! Good luck!