@JohnFromGWN
A few ideas:
core.ypt:
The thread I posted above (this one) suggests the particle textures exist within 'core.ypt'.
I'm only going by what Aurora11 said, but he used the 'core.ypt''s I posted & they appeared to have at least reduced/changed the effect.
The links to the 'core.ypt' files are still active in that thread, maybe try them out in your game (after backing up 'update.rpf', install over all three 'core.ypt's etc) & see what you get?
Might not be all of the problem, but somewhere to start anyway.
@JohnFromGWN said in Who passed the wind? This is SO annoying!:
doesn't make sense if this file is deleted or renamed because game still loads as does particles of crap
I've seen evidence GTA V has a lot of redundancy built into it. Removing files isn't the best approach.
Much better to edit the file the game is loading to confirm things, otherwise you don't actually know what the game may be doing/where it might be getting things from etc.
Example:
- Say there is a script somewhere that initiates the wind particles, but uses textures in 'core.ypt'.
- You remove/delete the 'core.ypt' textures somehow, the script still runs, but can't find the textures & produces pure black untextured particles instead.
- Given they are so tiny, you're not going to be able to easily tell the difference between the textured & untextured particles & thus, think it has nothing to do with 'core.ypt'.
- Just a theoretical example, but you get what I mean, I would go back & test 'core.ypt' by editing all the textures, certainly all the ones that contain 'debris' or 'paper' in the name (6 textures or so in total)
- Just make them bright neon pink/green/different colours etc & test in-game etc. Pretty quick/easy to confirm what is what & then work from there/rule it out completely etc

procedural.ymt/.meta:
@ReNNie is right, if you rule out 'core.ypt' thoroughly, worth having a look at 'procedural.meta' also 
Don't delete/remove the file tho, as the game may well fall back to & use 'procedural.ymt' instead, rather just make it empty etc:
Example:
<?xml version="1.0" encoding="UTF-8"?>
<CProceduralInfo>
<procObjInfos>
</procObjInfos>
<plantInfos>
</plantInfos>
<procTagTable>
</procTagTable>
</CProceduralInfo>
GPU Driver:
Maybe try a Display Driver Uninstaller (DDU) Safemode uninstall of your GPU driver also.
Reinstall normally after.
You may want to backup any custom profiles beforehand.
Settings:
Have you tried your game with AA = OFF? Just diagnostically, in case it's making the effect worse/more noticable etc. Seen GTAV's AA cause issues on screen etc.
I'll also test my game out vanilla & see if they appear?...
Edit:
...Nah, they defo don't appear in my game
Would normally say something was wrong with driver/install (given they don't appear in everyone's game), but the fact that they react to the wind suggests they are a game mechanic.
That's the first thing that needs to be figured out. Is it actually a part of the game, or is something broken? If you can shut it down with a script, does suggest it's part of the game. 
Perhaps see what else you can confirm 