Long Sands • Statistics for September

September: Autumn's First Real Swell Windows

September is the turning point. Average swell height climbs back to 0.9m (3ft) and the period reaches 6.7s, and while that is far from winter-size, the frequency of organised swell begins to increase. The NNE direction remains dominant at 16.4%, but now N, NW and NNW start adding more north energy to the mix. The bigger sets - 1.5-2m (5-7ft) from the NNE and N - become more regular as the first genuine autumn lows form over the North Atlantic.

Wind quality also improves markedly. Ideal surf wind jumps back to 30%, with WSW and W winds dominating and only a modest onshore NE/ENE flow. The warm summer sea surface, still 14.5°C, combines with this clean west flow to create some of the most pleasant surf days on the calendar. Air temperatures cool to 13.1°C, but the ocean is still balmy by UK standards. If you pick the right September low, Long Sands can deliver chest-high, clean waves with only a handful of people in the water.