Conditions at Alvor in September
September: The Autumn Switch Flickers On
September is where Alvor starts to wake up from the summer nap. Average wave height is still small at 0.8m (2.5ft), but the period lengthens to 10.3s as the first Atlantic autumn lows begin to form. The swell rose is still NW-heavy - NW 39.8 percent, WNW 30.3 percent - yet the SW component increases to 2.1 percent and WSW to 3.8 percent, hinting at the seasonal shift. Ideal wind improves to 38 percent, with NNW 26.7 percent and NW 15.5 percent dominating the wind rose. Water temperature is still warm at 19.6°C, air averages 21.0°C, and rainfall rises to 0.75mm/day. The first true S/SW groundswell of the season often arrives in late September, and when it meets a light N/NNE offshore flow, Alvor can produce clean, hollow sandbar waves out of nowhere. It is a sneaky-good month for those who watch the synoptic charts closely.
Average Spot conditions at Alvor in September
Swell history for September
Wind history for September
Swell quality
Analyze the groundswell consistency at Alvor 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 Alvor for your next trip in September.
Ground swell
Ground swell by size
Wind conditions
Evaluate the wind and swell alignment at Alvor 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 Alvor.