The water temperature is essential and varies during the different seasons. Around 8-12 degrees are close to perfect, but during warm periods, it all happens during cool quiet nights, and very early mornings, where the water temperature drops.
These conditions are present right now in Denmark, so I have spent the last three nights fishing, and the day time trying to catch up with some zzzz's !!
Here is little photo essay from the last couple day's fishing at the north coast of what I call home.
PS. we didn't catch anything, saw some really nice fish 50 meter beyond our catching distance, but that's part of the game. Just being there is always a great experience. It's absolutely quiet and a very fascinating time of the day.