Many kokanee anglers believe the best bite for kokanee is in the morning, and they literally quit biting after 9:00 AM. Most experts disagree. They can catch kokanee all day long. You can mark kokanee at 20 to 25 feet first thing in the morning, and if the boating pressure is light the fish will stay within a five to ten foot band of the original depth all day long. Excessive boating pressure puts kokanee down. You may start the day at 20 feet but by mid day the fish often will have moved down to 60 feet or more to get away from all the commotion. If you drop to 60 feet, you will catch them again. Wind on the water seems to be another factor in mid day fishing. If the surface is white water heavily roiled by wind the fish will often stay near the surface. However, if the water is calm and the sun is high, they will usually go deep.
Kokanee will bite all day long. However they do have bite periods when they will bite exceptionally well. The solunar tables which tell what days and what times fishing is best often tell the story. They are based on lunar phases of the moon and tides. Weekdays are often better kokanee fishing days than weekends. The excessive weekend boat traffic, both from fishing boats and recreational boats creates such a din that the kokanee fishing is usually poor during the day light hours. The jet ski traffic is especially damaging to your catch ratio. If you are pretty much stuck with fishing weekends, being on the water in the dark and ready to fish at first legal light is probably your best strategy. As the boating pressure increases you will note the kokanee will get deeper and deeper.