Water thoroughly so moisture gets down to the depth of the roots. Exceptions to this general rule would be for newly seeded lawns where the surface needs to stay moist, newly sodded lawns that have not yet rooted into the soil of the site, or when summer patch disease is a problem. Given a choice, water early in the day when lawns are normally wet from dew. Avoid midday due to evaporation, and at night due to potential increased chances of some diseases. Spread the water uniformly across the lawn.
Sprinklers vary in distribution patterns, and require spray overlap for uniform coverage.
Placing coffee cans or similar straight-sided containers on the lawn can help measure water application rates. Avoid flooding areas, or missing other spots. To help conserve water use, mow higher, avoid excess nitrogen as warm weather approaches, limit traffic over the lawn, improve turf rooting, control thatch and soil compaction, and avoid pesticide use on drought stressed lawns.