The early morning starts can still pay off during July as can the evenings too, but much less so, since the water in the margins rarely has a chance to cool in the first part of the evening. You could try going upwind, but unless you can cast a hell of a long way, you are probably in for a frustrating time of it.
Weed-beds sometimes hold trout. You can sometimes see them if you drift a boat over them and spend your time looking sub-surface. Try floating fry the other side or in the gaps between weed. Or the dry fly. A big Whichham's comes recommended by some.
I have also read that you can make your own little holes with rakes attached to ropes (My Way With Trout - Arther Cove) and expect fish to arrive rather quickly . I have never resorted to this aquatic pruning, but I am known to be rather lazy in my approach to angling and so that may account for this.
If I am bank fishing, I tend to restrict my fishing time to the most likely hours. In order to do so this it helps to have a season ticket. However the dam can produce some really fine fishing, not every season, but often enough to give it a mention. It can always provide something, so total pessimism is unjustified.
I have three methods for the dams:
- HiD line and size #14 and #16 nymphs fished deep, often 15 ft down. If you keep hooking up with the wall then fish boobies.
- Floater and two leaded lures. Large cats whiskers and long leaders fished pretty much dead drift. Gives really hard takes. When it works.
- Floater and size #16 through #20 hot dries. Hot orange, red and claret Emergers. Can be great for bringing fish up to the surface. Even when nothing is showing.
If you get a cloudy day you may get some sport in the shallows. Normal techniques with nymphs and dries, as for the last two months, are the answer.