Typically do a fall fertilization. But it's still 100 every day and you aren't supposed to fertilize St. Augustine when it's this hot for fear of gray leaf spot.

After another couple of weeks, it'll be a waste of money to fertilize.

Plus, my yard is still suffering from the extreme heat and I doubt it would make good use of the fertilizer.

Should I go ahead and fertilize now, wait a few weeks, or blown it off altogether?

If you haven't already, subscribe to Neil Sperry's newsletters. He's in McKinney so he is able to give the right call for us when it comes to timing for fertilizer or pre-emergent. This was in this week's newsletter:

Now that weather is finally favorable for good turf growth, apply high-quality lawn fertilizer as prescribed by soil test. Use only if you have not fertilized within past six weeks. For most Texas soils that will mean an all-nitrogen food with 30 to 40 percent of that nitrogen in slow-release form. Water deeply after application.

https://neilsperry.com/2023/09/gardening-this-weekend-september-14-2023/

I'm waiting until next weekend when we're out of the 90s

Nitrogen, Phosphorus, and Potassium are the three numbers. I have been thinking about buying a home soil test kit with plug pole. Nitrogen in a 16-4-8. is 16 (.16) x 40 pound bag of fertilizer = 6.4 pounds of nitrogen.

Typical annual nitrogen program might recommend 1 pound of nitrogen per 1000 square feet.

If your yard is 3000 square feet divide by 1000= 3.
Multiply 3x6.4 = 19 pound of fertilizer to spread.

Maybe you can save product unless you have a large yard. This stuff is expensive.

I am thinking without a soil test, it is guessing. I like 16-4-8, April and August

It really depends on where you live. In Tarrant County, I have a clay soil that holds nutrients hard. So I use a 3-1-2 blend for initial fertilization (early April), and all nitrogen first of June and then - well, as this thread was started, a full nitrogen IF I fertilize in the fall.