Three numbers tell you most of what you need.
Swell height. How big the swell is out at sea, in feet or metres. It isn't the wave you'll ride; the beach, the tide and the seabed decide that.
Swell period. The seconds between waves. A longer period usually means swell from further away, with more push behind it. A short period is usually wind swell: choppy and weak.
Wind. Offshore wind blows from the land out to sea and holds waves up. Onshore blows from the sea and messes them up.
Small swell, short period, onshore wind: it's not on. Board out.
