Thanks Dave. I wondered if that's what it was; I pulled the leaves just after I took the picture. I'll grab some fungicide tomorrow.

Dave--or anyone else--I'm in LA, where it's supposed to be near or over 100 thru Wednesday. Should I wait for it to cool off a little before using Bonide copper fungicide on these?

Do it early morning or late evening. Never spray anything on the plant in the heat of the day.

Dave

Usually I'd spray just before sundown; my concern is just the effect of any residual coating on the leaves when it's that hot.

Here's another opinion: Doubt it's early blight. The lesions are different and don't show the concentric rings if it were early blight.

If your "LA" refers to Los Angeles, use this search phrase to see numerous images of the blight, but drop the quote marks:

"early blight tomatoes in los angeles california"

Thanks Jean. Part of me wonders if the leaves weren't injured by some nasty particulate blowing in from the construction site across the street. There's a lot of that kind of stuff that accumulates outside in LA, including on my balcony.