Well, we are in the middle of July 2013 and it is a HOT ONE! Your lawn will look its best if it is properly hydrated and mowed.
In the mid-Summer we recommend that you don't cut your grass too low. (It will certainly Brown-out) and you'll have not only dead grass but unfortunately unwanted weeds beginning to grow through your once lush carpet of beautiful green grass.
Our recommended cut height is approximately 3" in the dry hot days of summer.
Why? Because if you cut below 3" the little moisture in the ground and the high temperatures of mid-day will cause the grass to dry out (Brown-out). Also, this hurts the individual grass blades and allows weeds to germinate and get a foothold in the lawn.
Since most weeds grow faster than the grass, it won't be long before they overtake your once beautiful and lush lawn, and costing you more money to get rid of them in the Fall or early Spring.