Depends where you live too.
This morning I rode into 30 mph gusting wind all the way to work.
At 62 degrees. In a T-shirt and a mesh jacket. 45 miles.
Dumb lucky I had a nylon windbreaker in my bag.
There are also big bugs to consider.
Grasshoppers big as a clothespin, cicaidas big as a sparrow.
When I hear the smak! thru earplugs, over the bike exhaust and wind noise, and a bug-guts splash 3 inches in radius shows up on the windshield just below my eye line, I don't feel a bit wussy about wanting a low shield.
I do not want to have to look thru it, tho'
I have not been able to convince myself that any kind of saddle bags are equally tolerable. Stupid, I'll wear a backpack 2 days in 3 to get out of cluttering up the bike.