Just like in the winter with low temperatures, the grass is going into a dormancy stage.
21+ Fescue Grass Turning Brown. The one drawback is this: My fescue grass is turning brown.
Fescue Grass 101 What It Is And How To Grow It This Old House from cdn.vox-cdn.com
Improved cultivars look and grow like other popular lawn grasses, with the added benefit of being heat and drought. Grass turns brown when roots can no longer grab nutrients or water from soil, or when soil doesn't contain enough food or water. These grasses do not like high temperatures.
The one drawback is this:
Both bermuda grass and fescue can be used for a lawn, but they differ substantially in their appearance and their growth habits. Fescue grows well in meadows and pastures throughout north america, europe and north africa. Zoysiagrass is green in summer and brown in winter. Fine fescues are a subgroup of fescues distinguishable by their narrow, fine leaf blades.