In my over 68 years of fishing (I'm a good bit older than that) there have been signs that bass activity will be higher or lower than normal. It's seems to correlate with other wildlife. On some days/mornings/afternoon/ evenings, I've noticed that pond/lake activity is generally dead, nothing happening, not much moving. No birds, no frogs croaking, lack of insects. No surface activity on the water ~ dead. This seems to indicate poor fishing. On the other hand when you see an above normal surface activity of fish breaking and bait fish moving, that is a pretty good indication that activity is positive. Add birds moving, particularly fish hunting birds such as eagles, osprey, kingfishers and shore stalking birds, that's another plus. Add frogs croaking, snakes swimming, a variety of insects flying. This is the kind of day you will see or hear bass busting frogs or bait-fish up near the shore. This is the kind of day where small fish will continually hit your line were it enters the water. This is the kind of day you will catch 6 or 7 bass off that log where you usually only caught one. These are the times we would all like to be out on the water when things are "hot". Unfortunately these type of days (or times) seem to be the exception, not the norm.
When I was younger people used to ask me and my fishing buddy how we caught so many bass. The answer was, because we fish everyday. We would go fishing before we went to work. We would fish when we got off of work and fish on weekends, rainy days, hot days and sometimes at night. When you are doing that you just got to get into them at times. I particularly remember when we would be speed cranking Big-O's off a point and catch 25-30 nice bass, averaging 4 to 6, sometimes 7 pounds one right after the other. Being at the right place at the right time.
Is there anything else that you have personalty noticed that would indicate that it is going to be a productive day fishing?