I wrote last month about water temperature and boat electronics, but there are plenty of opportunities to find fish without relying on a surface temperature gauge. Knowing the various physical influences on localized water conditions can lead an angler to find those secret honey holes where the bass like to congregate.
As we all know, water rapidly absorbs heat energy. Shallow and surface waters, therefore, heat faster than deeper waters. Suspended particulate matter speeds up heat absorption all the more. Additionally, dark materials absorb more heat energy than light objects. Darker bottoms or dark submerged objects heat faster than lighter surroundings.
Dense materials absorb and hold more heat energy than loose, porous materials. Rocky substrates are generally warmer than sedimentary substrates of the same color.
Aquatic areas exposed longest to daily sunlight or, more accurately, the highest angles of incident sunlight, warm faster than more protected areas.
Water temperatures below the thermocline (boundary between warm surface and cooler deep waters) are too cold for summer bass.
Feeder creeks and tributaries can be warmer or cooler than the lake proper, depending on whether they are spring fed (as springs often maintain constant temperatures all year) and the type of runoff they collect. Power plants release warm-water discharges all year.
Warm or cold water can be moved around. Strong winds can drive heated surface water toward the windward sides of lakes, piling it onto the windward shorelines. On the leeward side of the lake, colder water rises from the depths to replace the displaced surface water. Shaded areas can be several degrees cooler than areas directly exposed to the sun.
By staying aware of these generalizations, you can make more educated guesses about where the bass might lie. If nothing else, they should help you know where not to fish. With that knowledge, you can approach a new lake or other unfamiliar territory and automatically eliminate a huge expanse of unproductive water. Sometimes knowing where not to fish helps as much as knowing where to fish.
Stay on the lookout, then, for such things as areas with distinctly dark bottoms or rocky substrates; large boulders, either fully submerged or partially exposed, lying on loose substrate; dark objects such as submerged stumps or tree limbs hanging in the water; warm water creeks emptying into a colder lake; shallow coves or man-made canals adjacent to the deep water; and shorelines that receive lots of sunshine, especially during midday.
It is difficult to go much beyond rough generalization when describing with any certainty where bass will lie. Bass distribution, and thus bass fishing, is so site-specific as to defy sweeping truisms. We can predict where the bass will be, but that doesn't mean they will always be there. Fish long enough and you will find bass play by a different set of rules.