This is the real surface fly fishers month. Many an evening I have witnessed splendid rises where every fish was takeable, yet only to see a very small number of fish actually caught. And all caught fish coming to a very few anglers.
If the fish feed well in June, then the angler who knows his stuff will really get into fish. It is probable that the fish will shun joke-flies in favour of imitative patterns. And equally probable, during a rise, for the fish to select dries to the exclusion of all else.
June will see the start of the bank anglers turning to boats for the best fishing.
It is often the case that the fish will have vacated the margins during this, and the following warmer months, for the most part of the day. However, there are times when it is quite possible to do rather well from the banks during the summer. Generally this is during the first two or three hours after dawn and the last hour before dark.
Failing that you may have to go and fish off the dam (if there is one).
However, as is the way of these things, the trout often choose to rise some fifty yards from the dam, which is outside my casting range (!), and this can be so infuriating that you find that you must go and get yourself a boat after all.