Early bird gets the trout
Temps are soaring this week. Fisheries around the region will heat up in the afternoon, some to the point they are too hot. Mornings will be best during the heat, as they always are during this time of the year. Some fisheries like the Spokane will fish good in the evening too since it is cold from aquifer recharge. The Kootenai in Montana fishes well in the evening since it is such a cold river. Mornings will rule though most everywhere.
How early? Well on the Spokane and other big rivers like the Clark Fork, you can be on it at sun rise. Higher up in the mountains maybe give it an hour or so after sunrise. I was on the Blackfoot River in Montana this past weekend. The higher stretches were very cool in the morning and starting around 8am was plenty fine. Local rives like the St. Joe and NF Coeur d'Alene will fish earlier.
By early afternoon most fisheries will be tough, fish will hunker down, the JV fish will come out to play. As the morning heats up and the big fish begin to sulk the best tactic for big fish will be to nymph. Sorry to tell you that, it's the truth. Find the faster slots run a bobber rig through there. Maybe try Czech nymphing? We got all that in-stock here.
Check the temps though and give 'em a rest if it feels too warm, it probably is. Some people say 70 degrees or warmer water temps are too high, some say 68 degrees. I'm not a biologist I just know how to catch them so I'd say if water temps are somewhere in the 68-70 degree plus range, probably time to call it a day and go have a beer or nap.
If you are on the water early you can still get a 6-8 hours of fishing in, get back home early in time for dinner, the wife will be happy and you will have got your fish fix in.