Conditions at Reef in September
September: The First Stirs of Autumn
September is a month of change. The average swell height is still modest at 5.2ft (1.6m), but the average period jumps back to 10.5 seconds - back into the powerful, long-period category. Swell directions remain northerly, with NW at 36% and NNW at 34%, but WNW is also well represented at 15%, meaning more of the energy is swinging into the optimal west-to-northwest window for the reef. We start to see the first true groundswells of autumn, often boosted by ex-hurricanes or early-season extratropical lows.
The wind situation also begins to improve. The offshore east to southeast quadrant accounts for 4.6% of observations, and ideal surf conditions jump to 14% - more than double July's figure. NNW is still the dominant wind at 36%, but it is lighter and less consistent than in summer. The water is at its warmest, 18.2°C, with air temperatures averaging 19.8°C. September is a hidden gem: still warm, still mostly small, but increasingly showing flashes of real autumn potential.
Average Spot conditions at Reef in September
Swell history for September
Wind history for September
Swell quality
Analyze the groundswell consistency at Reef during September. Based on historical data, there is a % probability of groundswell occurring this month. The chart below provides a detailed breakdown of the average wave height distribution, offering deep insights into the swell quality and surf potential you can expect at Reef for your next trip in September.
Ground swell
Ground swell by size
Wind conditions
Evaluate the wind and swell alignment at Reef for September. Our analysis shows that favorable offshore or side-shore winds coincide with surfable swell approximately % of the time. The accompanying graph illustrates the average size distribution of waves during these optimal wind windows at Reef.