Am I right in guessing this is sun damage?

[malteseproverb]

They were both in a large east facing window and have been there for a year but then this happened

[bethmarie]

That's what it looks like to me.

[DMT]

Did you or your neighbors cut/trim any trees that may have altered how much sun was coming in. Having your orchids on the East window for a year some other source altered how much light was coming in besides the changing of the seasons.

[malteseproverb]

No, there are no trees to cut and the rowhomes across the street are all still there! I think the angle of the sun must have changed and it's now barreling down on this window. Haven't seen any change in the plants upstairs but I keep higher light plants up there.

[PaphMadMan]

Yes, classic sunburn. And it often happens because of changing angle of the sun through the window, or in fall when trees lose leaves.

[estación seca]

It can also happen after a prolonged cloudy spell when it heats up and the sun shines brightly.

[NikkiM]

I see you're from Philly. I am from Reading, and the weather we have been having it is a good guess since it has been cloudy and stormy lately it is probably from the sun just coming back out at full force.

[estación seca]

My sun is much stronger than yours. I try not to let it hit Phals, not even in winter.

[malteseproverb]

I didn't know it could happen after cloud cover. That's interesting. I'll have to keep a close watch on some of my other plants. I've moved my phals for now.

[syspila]

Looks like a good sunburn to me.