Could be spider mites. Check with a magnifying glass.

Linda

Looks like a little sun burn. New growth looks good, nothing to worry about imo. You can remove the damaged leaves or the whole branch.

If sunburn, or other non-living cause, keep the leaf. The plant has very few leaves. At this time, it needs all the chlorophyll possible working on its behalf.

Thank you for the reassurance. I will sit tight and be patient.

I second Linda: check for mites.

They can't be seen with the naked eye by most people. You'll need a magnifying glass. Or tap the leaf sharply over a piece of paper and examine any debris that falls onto the paper to see whether any of the "dirt" is moving.

You REALLY want to make sure it's not mites because an infestation not stopped early can get out of control really fast.

Orange County is the sort of location where mites thrive.

It won't hurt anything to snip the affected leaves off, even at this stage. The new growth looks beautiful and, if there are mites on those leaves, best to get them off before they migrate to other parts of the plant. Tomatoes grow really quickly - definitely keep that pot in as much sun as possible if you only get 3 hours. It'll be interesting to see how it does!

Looks like sunburn to me.

I would not think twice about snipping off the affected leaves if I was concerned. That plant will probably replace them in a few days.

That paper tip is great, thank you. I don't have a magnifying glass but I used the digital zoom on my phone's camera to check out the little specks of dirt and none were moving.