With dry weather, people start wondering what is going on with their brown lawn. The first thing to realize is that when lawns go brown in the heat of the summer, usually due to lack of rain/water, they are not dead, they are just dormant.
Letting a lawn go dormant is ok. The length of time a lawn can be dormant without killing the turf depends on grass species, soil type, depth of topsoil, exposure (sun vs. shade), slope, etc. A lawn can usually be dormant for four to six weeks without losing grass. Moving beyond that time, expect to see some irreversible damage.
A dormant lawn is fragile.
If you are letting a lawn go dormant, commit to doing that. Bringing a lawn in and out of dormancy is very hard on it and exhausts its carbohydrate reserves.
Once we get beyond the 6 week mark without water, it might be a good idea to give dormant turf a light watering of 1 cm every week to help it survive. This amount of water will not bring it out of dormancy, but it will help it survive a long dormant period.
A lawn that is dormant without a light watering will go beyond dormancy.