Castle Bay, Northwest Arm, AK tide times
NOAA tide prediction station 9458907, 56.2317° N, 158.3470° W. Heights in feet above MLLW.
Today at Castle Bay, Northwest Arm, AK
Today's predicted high and low waters, sunrise and sunset for Castle Bay, Northwest Arm, AK load here from NOAA. Without JavaScript they cannot be shown: NOAA's own table for station 9458907 is at tidesandcurrents.noaa.gov. Everything else on this page is measured and does not change from day to day.
What the tide does at Castle Bay, Northwest Arm, AK
Across the 1411 high and low waters NOAA predicts here for 2027, high water averages 7.93 ft above MLLW and low water 1.51 ft — a mean range of 6.42 ft. Taking each day's higher high and lower low, which is the swing someone standing on the shore actually sees, the average is 8.72 ft.
On 93% of days in 2027 there are two high waters and on the remaining 25 days only one. Where there are two, they differ in height by 1.87 ft on average. Successive high waters are 12h 25m apart on average.
The largest daily swing of 2027 is 13.28 ft on 5 July 2027 and the smallest is 3.42 ft on 3 December 2027 , a factor of 3.9 between the biggest spring tide and the smallest neap.
Measured figures
| Mean high water | 7.93 ft above MLLW |
|---|---|
| Mean low water | 1.51 ft above MLLW |
| Mean range | 6.42 ft |
| Mean great diurnal range | 8.72 ft |
| Largest daily range in 2027 | 13.28 ft on 5 July 2027 |
| Smallest daily range in 2027 | 3.42 ft on 3 December 2027 |
| Highest predicted tide | 11.11 ft at 1:48 PM on 22 January 2027 |
| Lowest predicted tide | -2.96 ft at 9:38 AM on 4 July 2027 |
| Average gap between high waters | 12h 25m |
| Tidal pattern | mixed, mainly semidiurnal (1.93 high waters a day) |
| Position | 56.2317° N, 158.3470° W |
| NOAA station id | 9458907 |
Every figure above is computed from NOAA's published predictions for station 9458907 for the whole of 2027 (365 days, 1411 tides), not from a regional average or an estimate.
What MLLW means here
Every height on this page is feet above MLLW — mean lower low water, the chart datum NOAA publishes tide predictions against. It is the average of the lower of each day's low waters, taken over a 19-year period, so zero here is neither the sea bed nor the average sea level: it is a level the water drops below regularly. At Castle Bay, Northwest Arm, AK, 172 of the 706 low waters predicted for 2027 — 24% of them — fall below zero, the lowest being -2.96 ft on 4 July 2027.
Practically: a chart showing 6 ft of water here means about 6 ft at a mean lower low water and about 14.7 ft at a mean higher high. Add the predicted height for the moment you care about to the charted depth.
Where these predictions come from
This is a reference station: NOAA computes its predictions directly, from a harmonic analysis of water levels measured at this location, rather than by offsetting another station's table.
Daylight at this latitude
Castle Bay, Northwest Arm, AK sits at 56.2317° N. The longest day of 2027 here is 17h 41m of daylight on 21 June 2027; the shortest is 6h 54m on 21 December 2027 — a difference of 10h 47m.
Day lengths are computed with NOAA's published solar algorithm from the station's latitude and longitude. Clock times for sunrise and sunset are deliberately not printed here: they depend on the station's UTC offset, and this site takes that offset from NOAA's own answers rather than from a timezone table — so it is the live panel above, which has them, that shows the times.
Nearest other stations
- Chignik, Anchorage Bay, AK 7.9 km (4.9 miles)
- Chankliut Island, AK 18 km (11 miles)
- Hump Island, Kuiukta Bay, AK 20 km (13 miles)
- Nakchamik Island, AK 36 km (22 miles)
- Unavikshak Island, AK 47 km (29 miles)
- Kujulik Bay (North Shore), AK 48 km (30 miles)
Put these tides on your own site
One line of HTML shows today's tides for Castle Bay, Northwest Arm, AK on any page:
<script src="https://tidedata.romermade.com/v1/embed.js" data-station="9458907" defer></script>No account, no key, no build step. How it works.