This has been the year of turfgrass disease in Minnesota with the mix of humidity, heat and rain. The  fertilization level could be a root cause of the lack of vigor. 

There are a couple things going on, none are serious and none of which requires treatment at this time with any fungicide. The one thing you could do this weekend is put down a small application (1/2 lb of N per 1,000sf of 24-0-5 or 6) fertilizer with about 30% slow-release nitrogen. The grass will grow out from the diseases as the weather dries up.

https://extension.umn.edu/lawns-and-landscapes/lawn-care

https://extension.umn.edu/lawn-care/fertilizing-lawns
All the rain is probably depleting nitrogen in lawns. Also consider letting your lawn grow a little taller and mow when it is 3-4 inches and take off only a half inch. Doing so will promote a thicker lawn the needs less water. I am not wishing for another very dry summer but a little less would be welcome.