Summer is in full swing, but you may have noticed your lawn isn't.
If you lawn looks brown don't despair. Grass naturally goes into a semi-dormant state in the heat of the summer. Growth slows down and much top growth turns brown.
Notice the brown top growth is still moist however, so its not dead.
So unless your lawn is crunchy and dusty - don't worry, it will come back when the weather cools closer to fall.
I am sure you have noticed some lawns which still look green and thick. This is most likely due to regular watering, and I would bet the watering is from an in-ground system.
Home watering with a sprinkler can be helpful, and will help your lawn survive a drought. But its unlikely to keep it green and lush like an in-ground, timed system.
Personally, I don't water the lawn*. I let my grass do its natural thing in the summer, plus I don't like to waste a precious commodity on my vanity. (hmm, conservation vs. vanity hmm)
* except for newly seeded areas which may fail without adequate water