A lawn suffers from drought damage when water evaporates from the lawn faster than the roots absorb it. Drought damage occurs first in the hottest and driest areas of the lawn-along sidewalks, driveways, south- or west-facing slopes, south sides of reflecting buildings, and areas with sandy soil. Grass blades don''t wilt as broadleaf plants do. They don''t droop, but roll or fold up lengthwise.
Water the lawn immediately. If the grass has turned yellow, the affected areas will require several weeks to recover. If you are not very conscientious about watering your lawn, consider planting a drought-tolerant turfgrass.