The old saying is "you won't catch anything if your line's not in the water"!!!There's every chance you'll catch during to hottest, brightest part of the day but you'll increase your chances by fishing late in the evening and/or early in the morning. Also depends on what you're fishing for. If your fishing for game species...salmon, seatrout, rainbows, brownies etc then, by a long way your best chances are early and late unless it's seatrout then during the hours of darkness on a dark, muggy night ;-)