mmm all I could think of was the possibility of sunscorch through rain droplets on the leaf....but this is a wild guess and i have no idea of US pests and diseases.

Turn the leaves over. I suspect the spots, underneath, are a vivid rust color. That would be the fungal disease, RUST.

I REALLY hate Rust. And it is the biggest fungal disease, here in SoCal, where black spot is rare.

You don't provide your location, but if you are in CA, this is being a bad spring for rust. It may improve, later in the year. If not, if it continues to rust, or gets worse, I would not choose to keep it in my garden.

Jeri

Thanks all.

Jeri, I just looked under and it does appear to be rust as you described. Yikes. I've honestly never noticed rust on any plants here before. I thought it was common in the South and East coast, but never seen it in my garden before. I live in inland So Cal, so I hope the arid climate may help decrease the rust on it. That's 'Yves Piaget' by the way.

Rose rust is rare in the East and unknown in the South, because it doesn't tolerate warm summers. It's a disease of cool maritime climates, and it spreads only during periods of rain.

This article may be of interest:

Here is a link that might be useful: lack of silicone and rust on plants

I get rust on my roses and I'm located about 50 miles inland. Summer is scorching hot here with many days over 100 degrees, with over 110 not uncommon. The air is very dry unless its raining (and we don't get much!).

Here is one of my roses that gets rust. Archduke Charles. I bought him last year and planted him in a prime spot with full sun. He mildewed and rusted to such an extant that I couldn't stand looking at the diseased foliage. So I shovel-pruned him and replaced him last year with a rose (Irish Hope) that even in the same location has completely clean leaves (and I don't spray my roses). I didn't have the heart to destroy Archduke Charles. Rather I put him in a pot placed in partial sun in a rare spot that stays damp, wedged between a shrub and a tree. I reasoned he does well in the south and thus would be happier in a more humid environment. This year the mildew is greatly reduced but the rust is currently increasing, which is what happened last year at about the same time.

Blooms can be pretty:

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The same leaf, top:

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and bottom:

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More leaves:

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I think Jeri may have Archduke Charles but hers is clean-leaved. Yet she is near the coast. So go figure! This rose might be expected to be clean in my area, but it certainly isn't. I have plenty of other roses that have no rust at all ever. Even roses in close proximity to ones that rust.

Melissa