Alaska
Chowiet Island
Semidi Island · Alaska · NOAA station 9458519 · Tide predictions
56.0517, -156.6980
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48-hour outlook
Drag across the curve to inspect any time. Weather icons show the forecast at each high tide.
Drawn from the high/low predictions — NOAA publishes high/low only for this station.
The next seven days
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H = high tide · L = low tide · highs & lows in local time
On the water nearby
Last light, longer plans
Daylight calendar for King Salmon → Alaska Daylight · Northern lights forecast for King Salmon → Alaska Aurora Forecast
Nearby tide stations
- Chirikof Island · 40.7 mi SE
- Nakchamik Island · 47.6 mi NW
- Unavikshak Island · 50.2 mi NW
- Chankliut Island · 54.7 mi W
- Aniakchak Bay · 57.4 mi NW
Plan ahead
2027 tide extremes for this station
Highest predicted high tide: 10.9 ft — Fri Jan 22 · 12:34 PM
Lowest predicted low tide: -2.8 ft — Mon Jul 5 · 8:06 AM
Biggest single-day swing: 13.3 ft on Mon Jul 5
Best daytime minus tides of 2027
| Date | Low tide | Height |
|---|---|---|
| Mon Jul 5 | 8:06 AM | -2.8 ft |
| Sun Jul 4 | 7:20 AM | -2.8 ft |
| Sun Jun 6 | 8:18 AM | -2.8 ft |
| Sat Jun 5 | 7:31 AM | -2.7 ft |
| Mon Jun 7 | 9:05 AM | -2.5 ft |
| Tue Jul 6 | 8:51 AM | -2.5 ft |
| Mon Aug 2 | 7:04 AM | -2.4 ft |
| Sat May 8 | 8:28 AM | -2.3 ft |
| Thu Jan 21 | 6:45 PM | -2.3 ft |
| Tue Aug 3 | 7:47 AM | -2.2 ft |
183 minus tides (below 0 ft) are predicted here in 2027. The table shows up to the 10 lowest that fall between 7 AM and 7 PM — the ones worth planning a clam dig or tidepool walk around.
About this station
Chowiet Island, Semidi Island is one of NOAA's reference tide stations — its predictions are computed directly from harmonic analysis of water levels observed here, and other nearby stations are calculated from it.
Alaska holds the country's most extreme tides: Inside Passage channels, Cook Inlet swings past 30 ft, and Arctic stations where the tide is measured in inches and wind setup runs the show.