Backdoor - surf spot statistics

Best Surf Season (October - March)

The North Pacific roars to life as the Aleutian Low strengthens, sending a relentless parade of NW to NNW groundswells directly into the northwest-facing reef at Backdoor. During these months, average swell heights hover in the 2.4m to 2.7m range with long periods of 11-13 seconds, often delivering pumping, barreling waves that are the stuff of legend. The trade wind pattern also favours offshore conditions more frequently, with the easterly and southeasterly flow (E, ESE, SE) blowing cleanly across the lineup, keeping the wave faces smooth and the tubes hollow. January, February, and December are the peak months, with ideal wind frequencies reaching 24-27% – but even on days with some cross-shore influence, the sheer power of the swell makes for memorable sessions.

Fair Surf Season (April & September)

April and September represent the transition windows. In April, the swell engine begins to quiet down – average heights drop to 2.2m and periods shorten to 10.3s, but there are still occasional fun, rippable waves in the 1.5-2.5m range from the ENE and NE quadrants. The wind becomes more marginal: easterly trades still dominate, but ideal offshore percentages slip to 16%. September sees a similar pattern, with average heights around 1.7m but periods recovering to 9.2s. The trade winds strengthen in September, boosting the ideal window to 23%, making for some clean, punchy sessions on the better days. These months require a keen eye on the forecast to catch the windows when a good pulse aligns with calm morning trades.

Low Surf Season (May - August)

Summer slams the brakes on the North Pacific storm track. From May through August, average swell heights bottom out at 1.6-1.8m and periods drop to 7.8-9.2s. The swell direction rotates almost exclusively to the E and ENE, which are far from ideal for Backdoor's northwest exposure – these waves are short-period, choppy, and lack the power to wrap in properly. To make matters worse, the trade winds howl, with ideal offshore conditions occurring only 9-21% of the time. July is the absolute low point, with a pitiful 9% ideal wind and the smallest, weakest swell of the year. While there might be the odd fun-size, groveling session on a south wind day, this is primarily a time to save your energy for other spots or wait for the first autumn storms.

April: Transitional Mix

The North Pacific storm track begins to retreat in April. Average swell height drops to 2.2m and period shortens to 10.3s, meaning waves are smaller and less powerful, but still fun and rippable when conditions align. The swell direction shifts: ENE now dominates at 24.2%, followed by NE (17.5%) and NNE (11.7%). These are not ideal angles for Backdoor – they produce more windswell and less of the clean, wrapping groundswell from the NW. The wind is overwhelmingly from the ENE (37%) and E (36%), with ideal offshore windows dropping to just 16%. Light winds from the SE or S are rare. April requires patience and a careful watch for southerly wind shifts to unlock the best conditions.