A lawn should be watered in such a way that the lawn's roots penetrate deeply into the soil, 6-8 inches. Frequent watering leads to shallow root development, whereas, watering every other day or every third day promotes deeper root development. This is especially true in Colorado Front Range clayey soils. It is advisable to water for 5-7 minutes per cycle, and to repeat the cycle at least another time. Watering for extended periods of time leads to water runoff. Watering for short periods multiple times is more effective. Watering after midnight and before 9:00 a.m. is beneficial. There is less likelihood of water being lost because of warm temperatures and windy conditions. Kentucky blue grass can tolerate hot, dry conditions. The lawn is still healthy even if the grass turns a blue-gray color--an indication that water should again be applied. An easy way to check if the ground is sufficiently moist is to take a long (8 inches) narrow screw driver and push it into the soil. If the screwdriver goes in easily, the ground is sufficiently moist; if not, the soil probably needs additional moisture. Please check out the following fact sheets or garden notes: CMG GardenNotes #265, Fact Sheet no. 7.199, CMG GardenNotes #268, CMG GardenNotes #267, and Fact Sheet no. 7.202.