I am sure the weather there can get very nasty, however it wasn't too bad that day, Saturday 13th August 1988.
You can see in this other photo of the guy that was accepting the aircraft from us, he was only wearing a short sleeved shirt, no jacket or even a jumper.
I think it was more just for the official end of the ferry flight, and also our other stop earlier that day was at the Fokker Factory where they made big fuss of VH-FNR, it was the oldest F27 (then anyway) to ever return to the Factory.