That is drought stress

How much are you watering and how often?

Either you aren't watering enough, often enough, or the water isn't efficiently getting into the soil.

I am watering 1.5 inches per week if it doesn't rain. I have measured the amount about 3 times now and it has stayed consistent.

I noticed that the ground is very hard and compacted in that area, so I sprayed a surfectant over the weekend. today is my first day to water since then, and I doubt I will see a change yet. should I aerate that area now to allow for better absorption?

How often are you watering?

What did you spray as a surfactent? I would give it time and a couple apps to work. If it is really hard, an aerator might be a waste of time if it can't penetrate the soil.

Might run a soaker hose on a light trickle over the area.

I find that you just need to get water IN the ground and usually the rest will follow. But wetting a hydrophobic, rock hard soil can be tough. Not impossible, though.

Keep trying, and then revisit your watering schedule.

Watering once a week sounds all cool on the internet, but sometimes it doesn't work that way. Sometimes you'll need to water more often. Its OK.

Or maybe you need to put down more water per irrigation cycle.

But let us know how often you water and how much water you put down each time.

The soil is not rock hard, but it is noticeably harder than the rest of the yard. I water 3 days a week which is .5 inches each time.

I'm gonna get a soaker hose today and see if that helps, but I have a feeling that the soil is not absorbing the water.

Just before you water next stick a screwdriver into the ground in the problem area ans the good area. If the problem area needs more force to insert screwdriver then it is not getting enough water.