North Aleutian Basin lies off Alaska at 56.50° N, 161.50° W. Significant wave height there exceeds 2 m about 26% of the time across the whole year, roughly 8 days a month on average. The roughest month is November, with a mean significant wave height of 2.3 m and seas above 2 m about 54% of the time; the calmest is June, with a mean of 0.9 m and about 3.4% of the time above 2 m. Waves above 4 m occur about 2.3% of the time.
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Mean significant wave height and the percentage of time the significant wave height is above each level, by calendar month. The last row combines the months weighted by their length in days.
| Month | Mean Hs (m) | % above 1 m | % above 1.5 m | % above 2 m | % above 2.5 m | % above 3 m | % above 4 m |
|---|---|---|---|---|---|---|---|
| January | 1.8 | 86% | 60% | 34% | 17% | 8.4% | 1.9% |
| February | 1.7 | 80% | 52% | 30% | 15% | 6.8% | 1.6% |
| March | 1.6 | 76% | 49% | 28% | 15% | 7.8% | 2.1% |
| April | 1.5 | 70% | 41% | 22% | 11% | 5.4% | 1.7% |
| May | 1.1 | 52% | 23% | 8.7% | 3.1% | 1.1% | 0.2% |
| June | 0.9 | 36% | 13% | 3.4% | 0.9% | 0.2% | <0.1% |
| July | 1.0 | 39% | 13% | 3.6% | 1.0% | 0.3% | <0.1% |
| August | 1.2 | 59% | 27% | 12% | 4.8% | 2.3% | 0.6% |
| September | 1.6 | 79% | 49% | 27% | 14% | 7.0% | 1.5% |
| October | 2.1 | 91% | 68% | 44% | 27% | 15% | 4.9% |
| November | 2.3 | 94% | 76% | 54% | 36% | 23% | 7.7% |
| December | 2.2 | 93% | 73% | 50% | 30% | 17% | 5.2% |
| Year | 1.6 | 71% | 45% | 26% | 14% | 7.9% | 2.3% |
Wind at 10 m across the year: typically 7.7 m/s (15 kn), top 10% above 12.7 m/s (25 kn). Monthly means run from 5.5 m/s in July to 9.4 m/s in December.
Weather windows: a typical month fits about 20 separate 24 h periods with significant wave height below 2 m, fewest in November (about 10). Periods do not overlap, so a 30 day month holds at most 30.
Data basis: WAVERYS wave reanalysis (Copernicus Marine) + ERA5 wind, 1980-2023, 3 hourly. Data point 56.60° N, 161.60° W (0.2° grid), 13 km from the named position, 127,344 samples. Values are for the nearest grid cell and are not interpolated.
Generated using E.U. Copernicus Marine Service Information: WAVERYS global wave reanalysis [1980-2023], 3 hourly significant wave height, peak period and direction. Wind statistics from the ERA5 reanalysis (Copernicus C3S) on its 0.5 degree grid (wind, direction rose, diurnal cycle and ENSO split 1980-2024). Neither the European Commission nor ECMWF nor Mercator Ocean is responsible for any use of this information.
How the numbers are made: How it works. Other locations: all location pages.
Thrust Maritime, Sea State Explorer, North Aleutian Basin, WAVERYS wave reanalysis (Copernicus Marine) + ERA5 wind 1980-2023, 3 hourly, page built 2026-10-23, accessed [date], https://seastate.thrustm.com/locations/north-aleutian-basin.html
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