Conditions at Refsnes in September
September: Autumn's First Pulse
September is when Refsnes starts waking up again. Average swell height climbs to 5ft (1.6m) and the period lengthens to 7.6s. The ideal SSW-to-W swell window now accounts for about 31 percent of all wave observations, while NW and WNW still are the most common individual swell directions. The increased size and the slowly re-energizing Atlantic low-pressure track make September a genuinely exciting transition month, especially when a strong fetch develops west of the British Isles and sends building W/SW swell toward Norway.
Wind is still a limiting factor: ideal offshore conditions occur 16 percent of the time, with NNW winds remaining the dominant single direction. Yet the summer breeze patterns are weakening, and more autumn fronts bring swings through E/NE clearing winds. With air temperatures averaging 12.8°C, water still warm at 15.0°C and precipitation increasing to 4.99 mm/day, September offers the sweet spot for quality autumn surf before the real cold arrives.
Average Spot conditions at Refsnes in September
Swell history for September
Wind history for September
Swell quality
Analyze the groundswell consistency at Refsnes 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 Refsnes for your next trip in September.
Ground swell
Ground swell by size
Wind conditions
Evaluate the wind and swell alignment at Refsnes 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 Refsnes.