Hi Ed. It's not so much about the actual cut as it is about how much you cut and the condition of your lawn. Cutting a "dry" lawn too frequently during high temperatures can be stressful, and severe cutbacks are especially stressful. Mowing high puts much less stress on your lawn, promotes deep roots and helps reduce moisture loss. A good rule of thumb is to never remove more than one-third of the blade length at a time, and to mow the grass at your highest setting. (About 2 1/2 to 3 inches is best for most turfgrasses.) Ideally it's best to give your lawn about an inch of water per week. Otherwise the grass may thin, decline or even die. Bottom line is this: if you choose not to water during drought periods and your grass is going brown and dormant, then hold back on mowing. Otherwise, mowing high and mowing often will help a lawn to stand up to drought and even thrive in difficult conditions.