Cloudy days from early afternoon till late afternoon will be the fishiest time frame. Look for fish sipping on blue-wings and midges as the weather cools. There can be some excellent days of surface fishing this time of year, it's just a matter of being out there on the right day. Bring some small streamers or buggers too for those bigger fish hiding in the cut banks and in the debris. Look closely they can be tough to see, but once some fish are spotted you get the right swing/drift it could be a big fish on!