Nine Palms • Statistics for September

September: Hurricane Season and Powerful S and SSE Swell

September is the heart of the tropical cyclone season in the eastern Pacific, and the numbers reflect it. Average swell height remains high at 3.9ft (1.2m), period holds at 12.6s, and the S and SSW combo still covers around 91% of the distribution, but the SSE sector expands to nearly 6%-and that is where the most dramatic energy sits. The SSE direction shows 2.1% in the 5-6.5ft (1.5-2m) class, 1.2% in the 6.5-8ft (2-2.5m) class, and even a small 0.1% above 8ft (2.5m). This is the classic signature of distant tropical storms and upward-moving tropical waves projecting long-period swell toward the Mexican coast. Ideal wind frequency recovers slightly to 41%, but SE, S and SSW winds keep the surface mixed.

September is also the wettest month of the year, with 3.25mm/day of precipitation, while air temperatures stay warm at 28.5°C and water temperature peaks near 30.0°C. Expect variable conditions: one day can offer 4-6ft (1.2-1.8m) SSE groundswell with tropical rainbands blowing through; the next can be flat, hot and clogged with southerly winds. For advanced surfers, this is the month with the highest ceiling for XL excitement, but the consistency is poor and the surface is often far from perfect.