Looks like scorch. Mine weren't too fond of the 100+ September temperatures either, and some scorching happened on mine. But these are too tough of plants, especially if that is Agapanthus africanus, to use the word dying. More likely than not, it will bounce right back.

I don't know where you are located, but if it is in an inland/desert location, the plant may do better in a location with a bit of mid-day protection from the sun. I live in south OC, so there is an ocean influence, and my plants are mostly in half-day sun. But I see them thriving in full sun here also.

I don't think it looks like it's dying; just getting a lot of heat/sun and maybe not an ideal amount of water. But they are super tough, should be fine.

Give them a soak. They'll recover.