Conditions at Haleiwa in May
May: Trade Swell Takes Over
Summer starts early on Oahu. The average swell height at Haleiwa drops to 6ft (1.8m) and the average period tightens to 9.2s, signalling the end of reliable northwest groundswell. ENE swell is now the dominant source at 32.9%, with E at 20.3% and NE at 17.9%. The optimal N, WNW, NW, and NNW window accounts for barely 12% of all wave energy, which means Haleiwa is often left looking small and disorganized.
Winds are actually clean around 44% of the time, but that matters less when the swell is missing. The trades are relentless: ENE and E make up nearly 70% of the wind distribution, and even moderate 10-20kph winds add texture to the waves. Water temperature is warming at 25.2°C and air averages 24.3°C. For the surfer hunting bigger or more focused waves, it is a good month to look elsewhere.
Average Spot conditions at Haleiwa in May
Swell history for May
Wind history for May
Swell quality
Analyze the groundswell consistency at Haleiwa during May. 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 Haleiwa for your next trip in May.
Ground swell
Ground swell by size
Wind conditions
Evaluate the wind and swell alignment at Haleiwa for May. 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 Haleiwa.