The giant Salmonflies of the Western mountains are legendary for their proclivity to elicit consistent dry-fly action and ferocious strikes.
Joakim, perhaps someone on here will know better than I do. If Matt sees this he may comment. As far as I know, there is no way to predict snowfall and runoff this far in advance. It may vary in different locations, but I had planned to fish near Wolf Creek, and cancelled due to the pandemic. A buddy tells me they had heavy runoff in early July, and said it's just as well I didn't go. But there was no way to know this last July. It seems to vary from year to year in that area.
When is mid July for you and how close do you want to be to Whitefish? We are just about clear of run off issues this year and I’d say we are mid July. There are lots of good streams that clear up more quickly and some that you may want to fish if the water is a little higher. The Thompson River often is good earlier than the rest off Highway 2, maybe around an hour drive from Whitefish. If the water is down in time, the middle fork of the Flathead would be another good spot.
And if you are working with a guide, there are always some other options, such as some local lakes or wade spots, that they can point you toward even during the worst of it. Always fishing to be had ;)