That varies depending upon your usage, your comfort zone, the size of your home, and how efficient your home is. I have friends living in Cedar Park and Round Rock, some like to adjust their temperature in their homes to 73 degrees in the summer and some 80 degrees.
If you are looking to purchase a home I would suggest working with a local realtor, and when you find a home that you are interested in ask the seller, through your realtor, how much the seller pays for the utilities.
I hope this helps! Please give me a thumbs up or choose best answer if this helps!
Realtor & Certified Stager
United Real Estate