Your lawn is the best indicator of its needs, learn to read what it is telling you. One of the earliest signs of the need for moisture is that the blades will begin to roll up. Another is a change in color (that is not due to disease).

Assuming you are normally watering once per week, then grass1950 is correct. If you are watering every day, which is strongly not recommended, then You should watch it very carefully. At the first sign of heat stress anywhere, it all needs water.

thanks for your answers.
due to the clay based soil, and to avoid run off
I water every other day in the early morning in two cycles of one hour each for a total of 1" of water per week.
what type of color change could I expect to see and in what fashion will the grass blades roll up? I am not sure I understand.
will the grass look wilted?
thanks again

My KBG lawn turns slightly darker as it becomes drought stressed. Wilted isn't a bad descriptin. The leaves the leaves turn in on themselves--rolling up.
Through regular observation and over time you will learn what signs indicate your turf is not getting enough water.
If you are watering for an hour twice a day, I doubt you'll suffer drought stress.

I attempted to start watering my lawn 1" per week all on one day.
I've never done this with my 2 year old lawn and I think I put too much stress on it.

It has since stopped growing much and has brown spots in multiple areas. What should I do now?
I live in zone 9, CA and temps are getting to 100 now. I have a fescue/blue grass mix.