Only by eye, it looks like it's at 90 degrees

Unlike the old Defender you can't stop the wipers at the top of their travel to check the angle there, if you turn off the ignition with the wipers operating they always carry on and park at the base of the screen.

 

Thanks Lightning. I'll eyeball mine tomorrow and report back.

 

Its difficult to see the angle, even a slight offset can cause issues. You can always tell which direction it needs to be twisted by the direction it is going when it chatters.

 

Put the wipers in winter mode. That may help you get a better look. Also I think if you look in the manual there is a way to get them to stop mid-screen but it's pretty goofy.