In Florida I have always noticed that the first major amount of a warm rain in Dec. Jan. and Feb., followed by a warm front and a extended warm stable weather pattern for more than a week triggers the big bass to spawn. Bass do not all spawn at once in the south and in fact most fish will spawn several times a year in Florida , if conditions permit it.
A good rule of thumb is to average the low air temps, in the area that you live in and keep notes as to when the spawn starts or fish in your area become more active. Then look for a forecasted approaching warm spell that is forecasted in your area. Noaa has past weather data and it is easy to graph low air temps. A 30 day chart works well.
The middle of the lake water temps. can be very misleading as to spawn temps. and times of the spawn. It is a must to pay attention to the shallows because that is where the spawn takes place. The shallows both warm and cool quickly prespawn . Warmer than average temps, with overcast nights hold the heat best in the shallows and are a good clue to look for the spawn to take place.
Sitting and watching an area on a calm day instead of fishing it can put you on to a prime spot. Just because there are tons of fish in an area does not mean they will bite well at times, but in time in your area you will learn what to use and how to use it.