I see some blackspot. Do you spray a fungicide? I recommend Bayer Garden Disease Control for Roses, Flowers, and Shrubs--available at Lowes or online. (Do not confuse it with one of Bayer's "combo" products--which I am NOT recommending.) Follow directions. Water the day before and try to do the spraying earlier in the morning when there is little or no wind (so you don't get a dangerous faceful of it by accident). Wash clothes and self afterwards.

The yellow leaves will fall off anyway, but some of the green will not, even though they have spots on them. The Bayer Garden Disease Control will kill the spots (but those spots will remain) and also act as a preventative.

If you have an exceptionally heavy BS problem, you may have to spray again in a week or 10 days, but hopefully that is all you will need for some time.

Kate

That is some type of rose fungal disease. You would have to post a nice clear closeup pic for others to know for sure what fungal disease it may be.

It is normal for SOME roses to get these fungal diseases then to drop some or all of its leaves over a period of time.

Options in your case are to just ignore it and sooner or later the rose bush will grow new leaves.
OR
Spray leaves with a fungicide on a regular cycle throughout the growing season...

I choose not to spray here so someone else can help you with that info...

There is some black spot and I think I can see the start of some powdery mildew problems too. Look for the Bayer Rose Disease Control product (NOT the 2 in 1 or 3 in 1 products!) and give it a good spray following the instructions on the bottle carefully. If you are experiencing hot humid days and cool nights that's the perfect weather for these fungal diseases to show up.