I have always believed that there are no hard, fast rules for bass fishing. There are certain things that should work under certain conditions, but not always. That is why it is so important to assess the situation and adjust accordingly.
BUT Catt has posted an excellent topic here about the spawn which is a a complex and confusing subject and we were having a great discussion until I sort of steered this in a different direction. I think maybe it is time we get back on topic. I would love to hear from other members about their experience about the spawn in their area, and what they watch for as a trigger. One thing I am sure of is this whole thing varies greatly geographically. What happens in the south is certainly different from the north. I agree that bass would spawn in extreme conditions, they would have to adapt or they would perish. But I don't think you would have a good spawn or a hardy population. Rolo speaks of bass spawning over a six month period in Florida with a great deal of temperature fluctuation. I don't think that could ever possibly happen in the north or most other places in this country, yet I believe what Rolo says about his area.
And I agree that it takes more than one thing to create a trigger for the spawn. I still believe that temperature is the most influential because bass are after all cold blooded creatures. I think The moon phase is a close second and can really make things pop when a full moon occurs at just the right time. The length of day light is not a big consideration as far as I am concerned because in all of the years I have fished, and all of the fishermen I know not one has told me that you need to be on the water when daylight reaches ten hours and forty seven minutes or so on. I believe that bass will spawn without a change in daylight hours as long as the temperature and moon phase are right.