To my eye, yes, it looks like leaf spot on tall fescue. (It also looks like you need to sharpen your mower blades. 🙂)

Warmth and the rain sets it off in my lawn, and it doesn’t go away until it starts drying up. It’s been awhile but last time I checked, there wasn’t any effective fungicide that was labeled for home lawns to treat it, so you’ll have to wait on the weather to change. There may be something available to those with a pesticide/herbicide license that’s not available to homeowners so it may be worth calling around and asking a few people.

What you can do in the meanwhile is ensure the healthy blades stay healthy by mowing regularly to encourage tillering (new blades from the same grass plant) and mowing high (3.5” if it is tall fescue). One thing I did was apply a very light amount of grass seed over the areas most affected every 3 weeks until everything was looking healthy again. Most of those seeds won’t germinate for awhile but will help build up a seed bank that will fill in the weak areas when conditions are right.

Haha, yes, I noticed the not so clean cuts as well. Sharpened the blades recently.

As for the leaf spot, I applied Scotts DiseasEx and it looks like the spreading has stopped a bit but, I think this is going to be an ongoing issue if I dont apply fungicide every month or so. The weather in central jersey has been on/off with the hot and humid rainy days.

I dont have much shade in my yard so anything that would seed and sprout now wont survive the summer.