Cardiff Reef - surf spot statistics

Best Surf Season (October - March)

The North Pacific comes alive during these months, generating consistent, long-period swell from the W and WSW that pours into Cardiff Reef. With an average wave period of 12-13 seconds and heights sitting in the fun to solid range (1-1.5m), the reef pulses with powerful, rideable waves. The real key, though, is the wind: offshore flow from the NE to ESE quadrant blows clean 22-50% of the time, sculpting glassy faces and making the most of every set. When a strong Aleutian low parks itself in the Gulf of Alaska, we see those epic, pumping days with waves in the 1.5-2.5m range. This is prime time — cold water, big skies, and consistent action.

Fair Surf Season (April & September)

These shoulder months are a mixed bag, as the swell pattern transitions. April still gets a decent dose of W and WSW swell (average 1.1m, 13.3s period), but the offshore wind window narrows to just 16%. You’ll often find a morning window with a light ENE breeze, but by mid-day the onshore flow kicks in. September sees the tail end of summer south swells from the SSW and SW, with average heights around 1m and very long periods (13.6s). However, ideal offshore winds are rare — only 6% of the time. When the stars align, those long-period ground swells combine with a morning offshore — that’s when you score clean, peeling lines.

Low Surf Season (May - August)

Summer brings a dramatic shift: the dominant swell shifts to the SSW and SW, primary from Southern Hemisphere storms and local eddies. While wave periods remain long (13.5-13.8s), the heights are small — averaging just 1.0m or less, most of it in the 0.5-1.5m fun-sized range. The real problem is the wind: offshore flow plummets to 1-4%, meaning the prevailing west to southwest winds (onshore) chop up the wave faces 90% of the time. Occasional early morning glass-offs with a light easterly can offer short windows, but overall it’s a struggle. Look for grindy small-wave boards and hope for a rare tropical storm pulse to break the monotony.

August: The Doldrums Deepen

August is the absolute low point for surf quality at Cardiff Reef. Average swell height dips to 0.9m — the smallest of the year. Swell direction is heavily focused on SW (46%) and WSW (30%), with SSW making up 17%. Period stays long at 13.6s, but the small size means the wave faces are gutless. Over 97% of the swell is under 1.5m. Offshore wind—once again—only blows 1% of the time. The wind is overwhelmingly onshore from the W (43%) and WSW (25%), most often at 10-20kph. The result is small, weak, bumpy surf. The only hope is for a passing tropical storm or a hurricane swell from the south to send a spike of energy. Without that, you’re better off finding a different activity.