The Washington area has received half an inch of rain so far this month, and with the lack of moisture many lawns are starting to dry. According to the Iowa State University Extension Office, most lawns in Iowa require one to one-and-a-half inches of water per week. It is recommended that when watering lawns, do so in a single application or two applications three to four days apart to avoid shallow rooting. Also, early morning is the best time to water a lawn, as it allows the water to soak into the soil with little water lost to evaporation.
Some cool-season grasses can survive long periods of dry weather, but are at risk of dying if dormant for more than six weeks.