Waimea seasonal overview
Best Surf Season (October - March)
Waimea fires best when the North Pacific comes alive, and from October through March the region is squarely in the crosshairs of powerful extratropical storms. Average swell heights climb above 2.0m, peaking near 2.7m in December and January, with periods consistently in the 11-13 second range—pumping and very powerful by our metrics. The dominant swell directions are a classic winter mix of NW and NNW, both ideal for the west-north-west facing coast. Offshore winds from the east and southeast are common, especially during high pressure setups, giving ideal surf conditions 22-28% of the time. This is when Waimea lives up to its legend: heavy, long-period groundswells wrapping in, groomed by clean offshore breezes, producing epic, pumping waves that challenge even the best.
Fair Surf Season (April - May & September)
As the seasonal transition ramps up, April, May, and September offer a mellower but still rewarding window. Swell heights drop to the 1.8-2.2m range, wave periods settle around 9-10 seconds, and the dominant swell shifts more toward NE and ENE—which aren't optimal directions but can still produce rideable lines, especially when combined with a bit of NW energy. The trade wind inversion strengthens, and ideal offshore wind percentages hover between 17-25%. While the consistency and power are lower than mid-winter, these months yield plenty of fun, solid days with lighter crowds and a more forgiving size. Good for logging and refining your technique on the famed Waimea walls.
Low Surf Season (June - August)
Summer is the quietest time at Waimea. From June through August, average swell heights bottom out at 1.6-1.7m and periods shrink to 7.8-8.2 seconds—average, punchy, rideable at best, but often choppy and messy. The swell direction is overwhelmingly from the ENE (over 50% of the total), which is far from ideal for this exposed NW-facing spot. Meanwhile, strong trade winds from the same ENE/E quadrant blow consistently, but only 10-15% of the time are they light enough or perfectly aligned to be considered ideal. The result is often weak, short-period windswell with a bumpy surface. Summer is a quiet season for Waimea, best left to longboarders and those seeking small-wave fun; the truly good waves are few and far between.
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Conditions at Waimea in September
September: Fall Freshening
September signals the beginning of the end of the summer doldrums. Average swell height rises to 1.7m and period jumps to 9.2 seconds—average, punchy, rideable. Swell directions start to diversify: ENE still leads at 46.2%, but NNE (9.1%) and NE (18.1%) contributions increase, and NNW makes a comeback with 5.5% (including some 1.5-2.5m waves). This hints at early North Pacific activity. The ideal wind percentage leaps to 25%, tied with January's peak. While winds remain trade-dominated (ENE 44%, E 41.5%), there are more frequent light wind windows, especially in the mornings. September offers improving prospects, with occasional fun, rippable waves when a early-season NW swell sneaks in under the trades. A promising month for patient surfers.
Average Spot conditions at Waimea in September
Swell history for September
Wind history for September
Swell quality
Analyze the groundswell consistency at Waimea 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 Waimea for your next trip in September.
Ground swell
Ground swell by size
Wind conditions
Evaluate the wind and swell alignment at Waimea 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 Waimea.
