Have you had a soil test done?
How much organic matter is in that soil?
How well does that soil drain?
How well does that soil retain moisture?
What kind of life is in that soil?

The grass is dry. That can happen from not enough moisture or from rotten roots not letting the water up. Are you getting puddles of water in the dry areas? Puddles can allow fungal rot to set in. If no puddles then the areas are not getting enough water. That could be due to sprinklers not adjusted right, runoff from hydrophobic soils, sandy soils allowing moisture to run through, or simply the idea that you need more than 1 inch per week this time of year.

My guess is your sprinklers are not adjusted right. That's more of an educated guess because I can see what appears to be a circular shape on the grass in your big picture. Mid way up from center to the right side of the picture is a nice colored circle(ish) green. Outside of that is the dry area. If you put cat food cans perpendicular to the circle and turn on the sprinklers, you will probably see that the cans are not filling evenly.