Guam (Apra Harbor), GU Tide Chart
Today's high and low tide times for Guam (Apra Harbor), GU — see the next high and low tide, water heights, and a live tide chart, straight from NOAA.
On Sunday, August 9, Guam has high tides at 2:35 AM (2.5 ft) and 6:22 PM (2.4 ft), and low tides at 10:31 AM (−0.2 ft) and 10:52 PM (1.9 ft). These are NOAA astronomical predictions in Guam local time, with heights in feet above MLLW.
It's 12:25 PM Chamorro Standard Time in Guam (Apra Harbor), GU.
Tide chart
How to read this chart
Pick the number of days with Days · hold or Zoom out to slide to other dates · tap the curve for exact heights.
Dark bands are night. Heights are feet above MLLW; times are the station's own local time.
Not a flood, navigation, or public-safety forecast.
Tide times and predicted heights: NOAA CO-OPS.
See the numeric tide table below.
Guam (Apra Harbor) tide times for Sunday, August 9
| Tide | Time | Height |
|---|---|---|
| High tide | 2:35 AM | 2.5 ft |
| Low tide | 10:31 AM | -0.2 ft |
| High tide | 6:22 PM | 2.4 ft |
| Low tide | 10:52 PM | 1.9 ft |
Predicted heights above MLLW (mean lower low water), in Guam (Apra Harbor) local time, from NOAA station 1630000. For any other day, use the chart above. Refreshed daily.
The sun and moon behind these tides
This station sits away from any city with its own sun and moon pages, so there are no local times to link to. The tides here are still the moon's doing, with the sun adding to or working against it — which is what the simulator shows.
Also see the Sun, Earth & Moon movement simulator, to watch how the three move together over a day, a week or a month.
Next king tides
The biggest predicted tides of the coming year at this station, and the lowest-water windows that typically follow — periods with some of the highest predicted astronomical tides of the year. Consult official local forecasts and alerts before planning any beach, boating or shoreline activity.
Computed from a full year of NOAA predictions: the top 10% of high tides, grouped into date windows.
Sun & moon
Spring tides follow the new and full moon: see the full moon calendar or today's moon phase.
Find high tides by date
The next 5 days to start — every high and low. Add 5 more days as many times as you like, or pick any range up to a year out.
What the tides are like at Guam (Apra Harbor)
Guam (Apra Harbor) has two high tides and two low tides most days — a mixed tide pattern, cycling at uneven intervals. The two highs (and two lows) each day are often noticeably unequal — a higher high and a lower high. The tidal range here is small, typically 1 to 2 feet. For the exact heights and times today, read them straight off the live chart above — it's drawn from NOAA's harmonic prediction for this station.
About Guam (Apra Harbor)
These coordinates are what every time on this page is solved for — sunrise, moonrise and the rest are computed from this exact point, not from a regional average.
About this station
NOAA station 1630000 (Apra Harbor) sits at 13.44, 144.65 on the western Pacific (Guam). Predictions on this page come straight from NOAA's harmonic model for this station — heights in feet above MLLW, times in the station's local time. Conditions a few miles along the shore can differ, so pick the station nearest where you'll actually be.
Nearest stations: Pago Pago, AS (3606 mi) · Kauai (Nawiliwili), HI (3713 mi) · Honolulu, HI (3810 mi) · Maui (Kahului), HI (3901 mi) · Hilo, HI (3997 mi)
Official source
For anything safety-related, go straight to NOAA's own prediction page for this station, not this page — and see what an astronomical prediction leaves out before you rely on the times above:
More tide stations
How many tides a day does Guam (Apra Harbor), GU get?
Guam (Apra Harbor) typically gets two high tides and two low tides each day — a mixed pattern. Exact times for today are on the live chart above.
What is the tidal range at Guam (Apra Harbor), GU?
The range between low and high water at Guam (Apra Harbor) is small, typically 1 to 2 feet. The chart above shows the exact predicted heights for the days you pick, straight from NOAA station 1630000.
Where does the tide data come from?
Straight from NOAA CO-OPS, the official U.S. source for tide predictions — for Guam (Apra Harbor), GU it uses the NOAA station listed above. Heights are in feet above MLLW (mean lower low water, the standard chart datum) and times are shown in the station's own local time.
How far ahead can I see the tides?
Tide predictions are computed from astronomy (the positions of the moon and sun), so they're available about a year ahead. Use the date-range finder to list every high tide between any two dates — for general reference and low-risk scheduling only. Before any marine or shoreline activity, confirm conditions with official local forecasts, alerts, harbor guidance, and NOAA.
What is a king tide?
An informal name for the highest tides of the year, which happen when a new or full moon lines up with the moon's closest approach to Earth. In the finder, the top 10% highest tides in your range are marked with a crown — periods with some of the highest predicted astronomical tides of the year.
What actually makes the tide bigger or smaller?
The engine is gravity: the moon and sun pull the ocean into bulges. When they line up at a new or full moon you get the biggest swings (spring tides); at quarter moons their pulls partly cancel (neap tides), and the moon's closest approach (perigee) super-sizes things further — that's a king tide. River flow, the shape of the bay, and long-term sea-level cycles can also affect the actual water level, which is why real conditions can differ from the astronomical prediction shown here.
What are the highest tides in the world — and in the U.S.?
The world's largest tides are in Canada's Bay of Fundy, where the range between low and high can top 50 feet (it's outside NOAA's network, so it isn't listed here). In the U.S., the giants are Alaska's Cook Inlet — Anchorage sees swings around 26–30 feet — along with Southeast Alaska ports like Skagway, and on the East Coast, Eastport, Maine at roughly 18 feet. All of those have dedicated pages here.
Can I save my home beach and other spots I follow?
Yes — tap ＋ Add to Saved Stations next to any station's name (it turns into a green Saved note), or ＋ Add nearest inside the Saved Stations dropdown to add the station closest to you (allow location access). Your saved spots appear as one-tap cards on the tides home page, the Default column's radio button picks your primary station, and Edit removes stations. Everything is stored on your device; no account needed.
Is this free? Do I need an account?
Completely free, no sign-up. It's built on public NOAA data and works on any device.