What time of day is best for watering the lawn, and for how long?
Weld County Colorado
The best time of day to irrigate your lawn is between 10 p.m. and 6 a.m.
If it is not practical to water during this time period, another option is to water between 9 a.m. and 11 a.m., starting the irrigation after the dew has dried but before the winds begin.
From a disease prevention perspective, irrigating anytime between 9 a.m. and 4 p.m. is fine (as long as the turf dries before the evening dew period sets in); however water loss from sun and wind will be greatest at this time.
The short answer to your question for how long to water an established lawn is, “water as deeply and as infrequently as possible.” For more information, go to https://extension.colostate.edu/topic-areas/yard-garden/watering-established-lawns-7-199/
For general lawn care information, go to: https://extension.colostate.edu/topic-areas/yard-garden/lawn-care-7-202/
Enjoy your lawn!