These days, with the weather being so varied, I rarely leave home without a beret, and I put lanyards on them.
I was beside the sea the first week of August and I was very glad to have a cover as I had to head upwind all along the sea front. It wasn't raining but it might just as well have been, and the gusts brought me to a halt.
A simple round cap - all wool, is easily rolled and carried and such a life saver when the weather turns nasty. Pulled down at the back it keeps much of the water from going the wrong side of the collar.

Of course your weather might be sweet and mild and a head covering not needed.

Anne the Pleater