What kind of grass do you have? The answer to that could save you hundred$. The following could save you more.

You don't need to aerate or dethatch, ever, and you don't need to fertilize right now. Aeration has only limited application to home owners. To watch TV or listen to the lawn care guys they would have you believe you need it twice a year. My lawn is 70 years old and never aerated. Dethatching is only something you do for dense Kentucky bluegrass that was watered too frequently and fertilized improperly. Almost nobody really needs that either. There are very few other circumstances where dethatching is needed. If you want to apply organic fertilizer, you could do that, but a chemical fertilizer would be a waste of money for many more weeks. Reseeding is only needed if you have fescue. If you do have fescue, I would suggest going to something like bermuda or St Augustine, which should thrive in your area with less irrigation.

If you're curious about your soil, Logan Labs in Ohio has the best soil test lab in the country. There's another good one at the University of Massachusetts and one in South Texas. Logan Labs and UMASS are better than the Texas lab and all the rest are a giant drop below those three. The standard, $25 test at LL covers all the micronutrients you should have in your soil. Once you get that done, post the results here and morpheuspa will help you understand what to do. He'll tell you what to apply, when, how much, and where to find it online.

How hot does it get in the summer? I assume 90s but do you get into the 100s?

Reseeding can't be discussed without knowing what grass you have and what you want, so I'll not comment on that.

Can you post a picture of the lawn showing some of the real grass and some of the weeds you need to get rid of? You might be able to spot spray with specialized herbicides rather than killing the entire lawn.

Your sprinkler installer likely set you up to water once or twice a day. This time of year you should not be watering more often than once a month. In the hottest heat of summer you will be watering no more than once a week, but when you water go ahead and apply 1 full inch every time. That deep watering takes care of the frequent watering cycle that the irrigation installers like to put you on. By watering only once a week you will develop deep, drought resistant roots in the lawn. It also breaks the weed cycle because weed seeds need daily water to germinate. If you start now getting used to infrequent watering, the grass will have developed the roots they need by the time it gets warmer.

Most grasses should be mowed a the mower's highest setting. That helps to take care of weeds by blocking sunlight to the soil where the weed seedlings are. If they can't get enough sun, they will die out.

Answer the questions and post some pictures and we can help you more.

Thanks for the tips. I do have a fescue lawn. In my area temperatures don't reach past 80's except for maybe a few days in the 90s. It's definitely never 100+ degrees ambient although some surface temperatures can reach that in direct sunlight.

Your thoughts about the pointlessness of aeration and dethatching are interesting. To me it makes sense that you want to break up compacted soil and remove some of the thatch layer so that water can get deeper. Maybe aeration and dethatching don't have much impact on a healthy, well established lawn but it seems like something you would want to do on a lawn you are trying to fix. I'll do some more research.

The same goes for watering. I would think that you can get away with less frequent watering on a well established lawn with deep roots, but I assumed I would need to water frequently as I'm restoring the lawn. I know I definitely need to water newly seeded areas until the seeds take root.

I'll try to post photos if time allows. Thanks for the tips!

Okay knowing it's fescue and your high temp is a big help. Fescue will do will where ever it is you are.

You do not have compacted soil unless you are playing football on soggy soil. Only football fields and golf courses are subject to compaction. Compaction requires repeated mechanical force on soggy soil to drive the air out. You don't have that. Physical aeration is really just a way for lawn care companies to make their boat payments. The golf courses soften their soil by using an expensive surfactant called Cascade Plus. It costs about $70 per gallon but really does the job. If you know anything about surfactants then you know that they are otherwise known as the ingredients in shampoo. You can get the exact same effect yourself at home by spraying any clear shampoo on your lawn. This "trick" has been in use for several years with complete success. The application rate is 3 ounces per 1,000 square feet. If you apply more by accident it will not hurt anything. Clear shampoo means something like baby shampoo and not Pert. Pert has conditioners that will not help your soil. Spray the shampoo on the lawn with a hose-end sprayer, and follow up with deep watering. That will carry the shampoo down in to the soil. Repeat in 2 weeks. If you want I can go into the biology of this process, but in brief summary, it helps the beneficial microbes reestablish their populations in your soil. Then they take over softening your soil for you. Healthy soil is ALL about healthy bacteria, fungi, protozoa, and micro arthropods.

If you are going to reseed this spring, you need to expect to get more summer weeds than if you reseeded in the fall. For you in your location, that is the only drawback to spring seeding. If you were in a warmer area, then I would caution that the new grass plants would not be able to stand the summer heat, but that should not be an issue for you.

If you have a lot of grassy weeds in the yard, you might need some special herbicides to get ready for seeding. If you have broadleaf weeds like clover or dandelions, then you should be able to get away with Weed-B-Gone. Spot spray the weeds only.

Fescue is the type of plant that does not spread like, say, Kentucky bluegrass. KBG will spread to fill in where the weeds die out. Since fescue does not spread like that, it is nice to have around flower beds. The problem with not spreading is that if anything damages the plants during the growing season, you'll have to reseed. In your area you can probably reseed any time from now through October and get some success. Normally fall would be the time to do it and completely avoid the summer weeds. And it's the summer weeds that will take advantage of thin spots in fescue.