Weather is often not constant for the entire round of golf, if sunny it gives a bit of shade , if wet a bit of protection and I keep my ball marker on it sometimes.
Keep my head warm on moderately cold days
Keep the sun from burning my head
Stop my hair, that I have, from blowing around and being a distraction
The peak keeps my eyes focused, reduces distractions.
Quite possibly there is an element of Pavlov's dog about this, play golf, wear cap, but I tell myself the above is the truth ?
Being very much a slaphead, I’m very wary of UV exposure, if it’s cloudy I’ll often go without, but if there is a hint of brightness on the cap goes, especially between April and October
Only if there is rain; if it's chilly, or if the sun is bright and low. Wore one today - chilly and windy, but it blew off a couple of time so had to tighten it up