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 today at 4:44 am. Next forecast at approx. 4:44 am.Get WillyWeather+ to remove ads