Possibly a roof issue. I am assuming it comes down the wall, from above and the window is an available opening. Or it could be the windows, that are not flashed properly. You have pretty large overhang on your eves, which does protect your windows a lot, so its more than likely coming from up above.

They aren’t flashed correctly. It’s always the flashing.

If it’s the flashing, is that fixable/repairable without redoing the windows?

I 100% agree that wimdows are not flashed properly. The fact you had windows replaced mean's the installer imporperly the windows and should have to reinstall them without charge to you. I would hire a recconized expert on weatherproofing to inspect and give a written report. If the report conclude's the problem is something other windows or window installation,have it addressed as the expert reccomend's. If there's a problem with windows or window installation,send contractor registered letter demanding they correct the problem within xx days of recieving letter. If the fail to correct it,file suit in small claims in the amount of 100% origional cost. Let me be clear,reflashing is a neccessary part of replacing roof,window or door and included in bid/estimate. Flashing as required is not optional. Any reputable contractor will walk away rather than doing an install or replace without addressing flashing. Please note,non of use said anything about caulking. Caulking is not a subsitute for missing or improperly installed flashing.

Christina, call a pro right away! The fact that you’re seeing this degree of damage almost always means the damage you can’t see is far more extensive than it seems. Water is traveling down the window and into the walls. There could be rot and mold. There’s a chance the mold will need professional removal. Please don’t panic - no one is going to die and the house isn’t going to fall down - I just mean to urge you to address this promptly and not mess around. It’s so unfortunate this wasn’t done properly.

I agree, it is usually the flashing but, usually when you have those large eve overhangs, it protects the windows from this happening, thats why the roof needs to be inspected too. It could even be a place high up on the roof that has a leak. However, if you had the windows installed, or if you installed yourself, please google, how to properly install windows, and and read all the info you can find, so you are informed on how it should be done. Yes, you also need to have the walls inspected for mold. After this many years, of water infiltration, it is almost certain, that you also have a mold problem in those walls. Too much moisture in walls, can be the cause of the way the siding looks like under those windows too.

You need someone to come out there that knows what they are looking at. Roof leaks "usually" show at the window head. What you are showing there could be either. Can we get some closer pictures and answers to Todd's questions. So far, he has the best observations in this thread.

Is that a perimeter J-channel vinyl window that is face attached to the wood siding?

By automatically claiming " the windows aren't flashed properly" is just ignorant.

Water can be coming from the siding or the roof and can migrate downward into the jambs.

Do not just assume its the window, I have seen countless instances where a homeowner insisted water was due to an improper window install and that turned out NOT TO BE THE CASE.

Given the condition of the siding, could these windows be on the weather side of the house? The side exposed to prevailing wind & wind driven rain?

Do the windows on the opposite side of the house leak?

Was any siding removed when the new windows were installed?

I don't see any head flashing on the windows.

Do the gutters over flow during rainstorms?

I don't like the gutter connection to the downspout in the upper right corner. Are all of the connections like this one? Sharp 90 degree bends and looks undersized.

I also note tropical vegetation so what is the annual rainfall amount?

Thank you for all the comments! They’re extremely helpful.

The windows are absolutely on the rainy side of the house - the rain hits that wall at a 45 degree angle and the eves are pretty useless on that side. Water comes in sideways directly at the windows. There aren’t any problems with rain leaking at any other windows of the house.

A few inches of siding around the perimeter were removed to install and then a border was added around them. Since the siding is weathering mostly below the windows and not above, I would guess it’s the flashing but I’ll try to look into this further.

"I would guess it’s the flashing but I’ll try to look into this further."

Windows need to come out to replace and or properly flash the windows. I would get a contractor in to do some poking around and selective demo to see if he can locate the exact point of water intrusion.

You might never know but obviously something has to change. I had the same issue with a lower window south facing rain direction too. I had a 2 story the window above no problem. So diagnosis depends on who comes out. One told me it was the home builder when installing the screens punched through the siding into the interior of wall.

Another the the flashing was wrong on the window above and was leaking down through wall. I used the third and let him open the damage and go above to see what was happening. He got open about a foot and stopped because everything was dry above.

So we ended up removing all screens sealing all drilled holes and adding more stucco sealing all windows twice then painting exterior with elastomeric paint. Redoing screens more sealing. Not me contractor.

Had huge rainstorm about three weeks after and dry window.

then a border was added around them.

Was the 'border' flashing tape or are you referring to the trim--that looks like J Channel. Or the flat boards between the windows?

Was any siding removed from below the windows?

Oh - the border I’m referring to is a small piece of siding on all 4 sides of the windows, to cover the siding that was cut away.

Do the windows have a nail fin?

Yes to the nail fin :)

It looks like the windows are projected more than normal to the exterior, like someone installed a regular 3.25 depth frame where the previous was more shallow. If that's the case, the drywall return should've been trimmed back to accommodate instead of the window being projected on the exterior. I'm guessing that the weird looking trim pieces surrounding the windows may have something to do with that process... Hard to say for sure based on the pics, but that's what it looks like to me, amateur hour install. Certainly possible that the roof could be the issue as well. Best recommendation is to get a reputable professional out there to take a look.