Alaska
Castle Islands
Duncan Canal · Alaska · NOAA station 9451321 · Tide predictions
56.6433, -133.1520
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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
Cape Edgecumbe buoy · 110 mi W · Station 46084
Wind & wave reports →
Last light, longer plans
Daylight calendar for Petersburg → Alaska Daylight · Northern lights forecast for Petersburg → Alaska Aurora Forecast
Nearby tide stations
- Beecher Pass · 7.1 mi SE
- Anchor Point · 8.6 mi E
- Papke's Landing · 8.6 mi E
- Point Lockwood, Woewodski Island · 9.3 mi SE
- Turn Point · 12.6 mi NE
Plan ahead
2027 tide extremes for this station
Highest predicted high tide: 19.4 ft — Sat Jan 23 · 1:24 PM
Lowest predicted low tide: -4.2 ft — Mon Jul 5 · 8:35 AM
Biggest single-day swing: 23.0 ft on Sat Jan 23
Best daytime minus tides of 2027
| Date | Low tide | Height |
|---|---|---|
| Mon Jul 5 | 8:35 AM | -4.2 ft |
| Tue Aug 3 | 8:18 AM | -4.0 ft |
| Sun Jun 6 | 8:45 AM | -3.9 ft |
| Sun Jul 4 | 7:49 AM | -3.9 ft |
| Tue Jul 6 | 9:20 AM | -3.9 ft |
| Sat Jun 5 | 7:59 AM | -3.8 ft |
| Mon Aug 2 | 7:36 AM | -3.7 ft |
| Wed Aug 4 | 8:59 AM | -3.6 ft |
| Mon Jun 7 | 9:33 AM | -3.6 ft |
| Sat May 8 | 8:54 AM | -3.4 ft |
203 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
Castle Islands, Duncan Canal 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.