We visit Ontario Beach Park year around. We also come in the winter, on especially cold days after a very cold spell. I'll explain why shortly. Every time of the year offers a different experience. During the winter, after an especially long cold spell with wind or precipitation the jetty gets coated with ice.
Waves crash into the jetty and the resulting spray falls on the jetty's walkway and railing.
Each wave adds another coat of ice. This ice will sometimes build to a height higher than the railings. The ice will become slick and nearly impossible to walk on. Because there is no railing, one slip could be lethal. If you plan to visit the jetty during the winter, dress appropriately.