Conditions at Niijima in July
July: Summer South Swell and Afternoon Glass
July is similar to June but with a slightly longer period - 8.0s - and an even stronger south-southwest flavor. The optimal NE-SE quadrant makes up only 29.7% of the swell, led by SE at 9.8% and ESE at 9.4%; meanwhile SSW roars in at 20.4%, SW at 19.1%, and S at 13.8%. This south-heavy pattern is typical of the summer subtropical ridge, and it means Niijima is primarily picking up inconsistent Southern Hemisphere and local monsoon swell rather than true east groundswell.
Ideal wind rises to 21%, with WSW 22.6% and SW 20.7% dominating. Summer afternoons can be glassy offshore, especially late in the day. Waves are small - average 1.3m (4ft) - but the 8.0s period adds some punch, and a good SE swell under light WSW wind will wrap nicely. Water temps climb to 25.6C and air to 24.9C, making the summer wardrobe extremely light. Rainfall is 7.16 mm/day, usually in short convective bursts. Not a bowl of cherries for wave size, but the consistency of offshore wind makes July a decent month for small-wave fun and longboard cruises.
Average Spot conditions at Niijima in July
Swell history for July
Wind history for July
Swell quality
Analyze the groundswell consistency at Niijima during July. 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 Niijima for your next trip in July.
Ground swell
Ground swell by size
Wind conditions
Evaluate the wind and swell alignment at Niijima for July. 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 Niijima.