Brown Spots in Yard
Over the past month or so brown spots have started developing in my yard and on the edges of sidewalks. I don't water the yard and I have a service that mows and edges. Might the spots be from lack of water or grass being cut too short? Or something like grubs? My neighbors have similar spot, but not as distinct. It looks like those yards that have a lot of weeds aren't experiencing the same problem.
Montgomery County Maryland
Based on your photos this does not look like a disease or insect issue. It has really been too hot & dry for grubs. We cannot say for sure what the problem is. Some reasons for the brown spots may be planting the wrong turfgrass species, poor soils, possible dog urine injury, drought, close mowing, etc. See our website for more information http://extension.umd.edu/hgic/cultural-environmental-problems-lawns
You did not mention the type of grass you planted and if the lawn is established or new. If the lawn is new and was not kept watered this may be a factor. Turf type tall fescue is the recommended grass species and grows best in full sun to part shade. If you planted a contractors mix of different species some of the grasses may be dying out. Also, Some grass species can go dormant at different rates during hot, dry weather. If you have dogs, may be dog urine injury. Poor soils - not enough organic matter in the soils to promote root growth, or close mowing.
At this point it looks like some of the areas are dead and you will have to do some spot renovation or overseeding in early fall.
Test your soil if not done in the last several years. Results give pH, liming, and fertilization recommendations. You may want to test for organic matter in the soil. https://extension.umd.edu/hgic/soils/soil-testing
See our publications on lawn renovation and overseeding and our turfgrass maintenance calendar for more information on mowing during the growing season and during hot dry weather.