No I live in So. California it doesn't get that cold. That said as a surfer you'll be much happier with a surfing wetsuit vs. a dive suit. The neoprene is much more flexible and the suits are designed with movement in mind. You won't need anywhere near 5 mil a 1-2 mil suit will work fine. Just a 1 or 1.5 mil top or a short leg & sleeve springsuit to keep your core warm. You can find online sales all the time or visit a local surf shop.
Remember that when you sweat it's locked in.
West