See http://aqua.ucdavis.edu/dbweb/outreach/aqua/200FS.pdf
You can go on the internet and find lots of good studies regarding bass habits that are fact based.
Bass are bass or are they smallmouth, spotted, northern LMB or Florida strain LMB? The 4 basic bass have different seasonal habits due to where they live. You are up north where nortern LMB and smallmouth bass reside.
It's been my experience that smallmouth bass spawn in water between 58 to 62 degrees and LMB between 62 to 67 degrees. Nothing in nature is absolute so bass, like everthing else, bass tend to adapt to thier habitate. The full moon phase definately affects the major spawn and females tend to start to move up to the bedding areas about 2 days before the full moon cycle and continue for about 2 days after.
Large lakes will have different water temperaures depending on the depth of the lake, wind conditions and weather, so there may be 2 to 3 spawning cycles going on at different locations.
If bass spawn and the water column cools down rapidly due to extreme weather, the eggs take longer to hatch, up to 14 days. The problem with a long hatch period is survival of both the eggs and fry, due to egg eating predators. Water temperatue at 62 to 65 degrees at the depth the bass are using to spawn is ideal, the eggs hatch within 4 to 5 days with better chances of survival. Above 67 degrees the bass must share the area with bedding bluegill and carp, both are egg eaters that rob the bass nest, so the warmer the water gets, the faster the eggs will hatch, but there is more pressure on egg survival from predators. Mother nature can be tough and it's survival of the fittest. The early birds must protect the nest longer and the later gators must protect the eggs from hordes of bluegill and carp. The majority of the survivers are the bass that spawn during ideal conditions.
WRB