Surf forecastStatisticsHistorical report

Portrush seasonal overview

Best Surf Season (October - March)

The North Atlantic roars to life during these months, with average swell heights consistently over 1.8m and long periods of 10-12s. Powerful extratropical storms track across the Atlantic, sending consistent W to NW swell into Portrush's northwest-facing beaches. However, the trade-off is the prevalence of onshore winds from the west and northwest, which can ruin wave quality. Still, when a strong high-pressure system settles over the British Isles or a low tracks just right, the region can see offshore winds from the south and southwest combining with pumping, clean swell. That is when Portrush truly shines.

Fair Surf Season (April & September)

These transitional months see a drop in average swell size (1.4-1.5m) and period (9.3-9.7s), but a noticeable increase in the frequency of favorable offshore winds (16-18% ideal). The swell energy is more moderate but often punchy, and the wind tends to back off, offering more clean sessions. Spring and early autumn can deliver fun, rippable waves with less crowd pressure.

Low Surf Season (May - August)

Summer brings the smallest swell of the year, averaging just 1.0-1.2m with periods around 8-9s. While the percentage of ideal offshore wind climbs to 18%, the swell source is weak – often just local windswell or very long-period groundswell from distant lows. Most days are small but can be fun on a log or groveler. The predominant wind shifts more to the north and northeast, which can be cross-shore or even offshore, but the lack of size keeps the energy low. Consistent, clean small waves are the norm, not the exception.

Loading chart...

Conditions at Portrush in May

May: The Lull Before Summer

May settles into a more typical spring pattern: average swell height drops to 1.2m, and period shortens to 8.7s. The swell is smaller but still arrives from the optimal W (18.7%) and WNW (25%) directions, though a significant chunk of the WNW swell is in the 0.5-1m range (11.1%), indicating weaker energy. The wind is generous: ideal 18% of the time. Southerly and southeasterly winds become more common, providing decent offshore flow. However, the ocean is often sleepy. May is for groveling on small, clean peaks and enjoying warmer water, with the occasional moderate south-westerly swell providing a brief injection of energy. Patience is key.

Average Spot conditions at Portrush in May

Swell history for May

0 - 0.5
0.5 - 1
1 - 1.5
1.5 - 2.0
2.0 - 2.5
> 2.5 m

Wind history for May

0 - 10
10 - 20
20 - 30
30 - 40
40 - 50
> 50 km/h

Swell quality

Analyze the groundswell consistency at Portrush 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 Portrush for your next trip in May.

Ground swell

Ground swell by size

Wind conditions

Evaluate the wind and swell alignment at Portrush 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 Portrush.

Swell with good wind

Swell with good wind by size