If the weathermen knew for sure, they'd all be rich. Take the warmest, driest
gear you have.
Diving goggles might be useful in wind-driven rain. If you have the
gear, but don't need it, fine. If you need the gear but don't have it, not fine. We went transatlantic in June and despite multiple layers of
clothing, hats, socks & gloves, were cold for at least a week, even with a
heater on board trying to warm us up. You are further south, but night watches can be cold even in summer.