10-day surf forecast with Strike Scores for Pero Lefts, West Sumba, Indonesia
Pero Lefts is a highly consistent left reef break on West Sumba's south coast that holds as big as it gets. The swell refracts around the headland creating big bowl sections with ample tube time, making this one of Sumba's most rewarding waves for experienced surfers. The wave's consistency means it's rarely flat during the April-October swell season, providing a reliable option when exploring this remote island.
Best day in the forecast: 2026-08-10 with a score of 63/100 (Fair)
Marginal conditions: Average score 53/100. Surfable but not special. Consider other spots.
Good alignment: Swell from 225° is 5° off optimal 220°, still within prime range.
Marginal size: 1.6m is 0.9m from ideal 2.5m.
Moderate period: 14s meets minimum 12s but below ideal 16s. Some groundswell energy present.
Onshore/cross-shore: 10 km/h from 125° (SE). Destroying wave quality. Offshore range: 352°-52°.
Groundswell-dominant conditions (clean, long-period waves).
Surfable but not special at Pero Lefts. The 1.6m swell from 225° is workable, but conditions aren't ideal. Fine if you're local, but not worth a dedicated trip.
1.6m (5.2ft) swell from 225° (SW) at 14s period
Marginal size: 1.8m is 0.7m from ideal 2.5m.
Good period: 15s is 94% of ideal 16s. Clean, powerful groundswell.
Onshore/cross-shore: 14 km/h from 121° (ESE). Destroying wave quality. Offshore range: 352°-52°.
Surfable but not special at Pero Lefts. The 1.8m swell from 225° is workable, but conditions aren't ideal. Fine if you're local, but not worth a dedicated trip.
1.8m (5.9ft) swell from 225° (SW) at 15s period
Good alignment: Swell from 223° is 3° off optimal 220°, still within prime range.
Marginal size: 2.1m is 0.4m from ideal 2.5m.
Onshore/cross-shore: 14 km/h from 118° (ESE). Destroying wave quality. Offshore range: 352°-52°.
Surfable but not special at Pero Lefts. The 2.1m swell from 223° is workable, but conditions aren't ideal. Fine if you're local, but not worth a dedicated trip.
2.1m (6.9ft) swell from 223° (SW) at 14s period
Good alignment: Swell from 222° is 2° off optimal 220°, still within prime range.
Marginal size: 2.4m is 0.1m from ideal 2.5m.
Surfable but not special at Pero Lefts. The 2.4m swell from 222° is workable, but conditions aren't ideal. Fine if you're local, but not worth a dedicated trip.
2.4m (7.9ft) swell from 222° (SW) at 14s period
Local wind-generated waves (choppy, short-period)
Perfect alignment: Swell from 221° is within 5° of optimal 220°.
Marginal size: 2.2m is 0.3m from ideal 2.5m.
Moderate period: 13s meets minimum 12s but below ideal 16s. Some groundswell energy present.
Onshore/cross-shore: 12 km/h from 124° (SE). Destroying wave quality. Offshore range: 352°-52°.
Surfable but not special at Pero Lefts. The 2.2m swell from 221° is workable, but conditions aren't ideal. Fine if you're local, but not worth a dedicated trip.
2.2m (7.2ft) swell from 221° (SW) at 13s period
Good alignment: Swell from 217° is 3° off optimal 220°, still within prime range.
Marginal size: 2.0m is 0.5m from ideal 2.5m.
Perfect period: 16s is at or above ideal 16s. Long-period groundswell with maximum power.
Onshore/cross-shore: 10 km/h from 150° (SSE). Destroying wave quality. Offshore range: 352°-52°.
Surfable but not special at Pero Lefts. The 2.0m swell from 217° is workable, but conditions aren't ideal. Fine if you're local, but not worth a dedicated trip.
2.0m (6.6ft) swell from 217° (SW) at 16s period
Good alignment: Swell from 213° is 7° off optimal 220°, still within prime range.
Good size: 2.7m is within 15% of ideal 2.5m.
Onshore/cross-shore: 13 km/h from 126° (SE). Destroying wave quality. Offshore range: 352°-52°.
Surfable but not special at Pero Lefts. The 2.7m swell from 213° is workable, but conditions aren't ideal. Fine if you're local, but not worth a dedicated trip.
2.7m (8.9ft) swell from 213° (SSW) at 14s period
Onshore/cross-shore: 9 km/h from 118° (ESE). Destroying wave quality. Offshore range: 352°-52°.
Poor conditions at Pero Lefts. Either swell direction (213°), size (2.0m), or wind (9 km/h from 118°) is unfavorable. Consider other spots or wait for better conditions.
2.0m (6.6ft) swell from 213° (SSW) at 13s period
Very low confidence (8-10 day forecast, conditions may change)
Moderate alignment: Swell from 209° is 11° off optimal 220°, workable but not ideal.
Marginal size: 2.6m is 0.1m from ideal 2.5m.
Onshore/cross-shore: 6 km/h from 225° (SW). Destroying wave quality. Offshore range: 352°-52°.
Surfable but not special at Pero Lefts. The 2.6m swell from 209° is workable, but conditions aren't ideal. Fine if you're local, but not worth a dedicated trip.
2.6m (8.5ft) swell from 209° (SSW) at 14s period
Moderate alignment: Swell from 210° is 10° off optimal 220°, workable but not ideal.
Marginal size: 2.3m is 0.2m from ideal 2.5m.
Onshore/cross-shore: 10 km/h from 128° (SE). Destroying wave quality. Offshore range: 352°-52°.
Surfable but not special at Pero Lefts. The 2.3m swell from 210° is workable, but conditions aren't ideal. Fine if you're local, but not worth a dedicated trip.
2.3m (7.5ft) swell from 210° (SSW) at 13s period
Open-Meteo Weather API (wind/weather data)