Key to a good lawn in the summer when it’s hot, regular cuts, feed the lawn as instructed on the lawn feed & keep watering in the evening to keep the ground from drying up & cracking like in this photo. Grass like any other plant need regular water & clay soils need to be kept moist to stop drying & cracking. Use a sprinkler & keep rotating round the lawn area during hot dry spells. But only in the evening once the sun is off it or you will scorch the grass.