Half Moon Bay State Beach Swell ForecastUnited StatesCASan Mateo CountyHalf Moon Bay State Beach1-Day3-Day5-Day Graph Plots Open in Graphs Swell Height and Direction Forecast NOAA WaveWatch III Swell Period Forecast NOAA WaveWatch IIIHalf Moon Bay State Beach swell forecast issued yesterday at 9:48 pm. Next forecast at approx. 9:48 pm.Get WillyWeather+ to remove ads