Where are you at? At least what zone? Has it been very hot where you are? It looks like burn to me. If not from heat maybe from spraying something?

I am in Palo Alto, in Silicon Valley - Zone 9. I haven;t sprayed it recently, and though it has been a little hot, I think it get enough water (daily).

Too much fertilizer? I don't really know--just guessing.

Kate

My two DD's look like that and it is heat this time of year. I find leaves on DD to be highly sensitive to just about everything. Sun and heat.

That's undoubtedly sunburn. When heat waves are predicted, give your rose a soaking at the roots on the first day of the heat spell. That will help.

Did you fertilize recently? If so, flush the soil with plenty of water. Excess nitrogen in ammonium form produces this look. Heat, scant water, and fertilizer can all contribute to burn. The plant will recover.