Tides Today & Tomorrow in Roche Harbor, San Juan Island, WA

TIDE TIMES for Monday, September 21, 2026
The tide is currently falling in Roche Harbor, San Juan Island, WA.

Next low tide : in 1h 28m at 7:36 am (0.9 ft)
Next high tide : 4:00 pm (7.2 ft)
Sunset today : 7:12 pm
Sunrise tomorrow : 6:58 am
Moon phase : Waxing Gibbous (76% illuminated)
Tide Station Location : Station #9449834
Common Questions About Tides

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Roche Harbor Resort and Marina

Roche Harbor, San Juan Island, WA Tides - Sep 2026

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Date		High Tide				Low Tide				Sun		Moon	Date
Date		AM	ft	PM	ft	AM	ft	PM	ft	Rise	Set	Moon	Date
1	Tue	8:45	6.1	8:07	7.4	2:09	0.9	1:55	3.8	6:30	7:54		1	Tue
2	Wed	10:02	6.0	8:34	7.4	2:56	0.1	2:37	5.0	6:31	7:52		2	Wed
3	Thu	11:43	6.1	9:03	7.2	3:48	-0.5	3:28	6.0	6:33	7:50		3	Thu
4	Fri			1:39	6.4	4:47	-0.8	4:42	6.7	6:34	7:48		4	Fri
5	Sat			2:57	6.9	5:52	-1.0	6:30	7.0	6:35	7:46		5	Sat
6	Sun			3:46	7.3	7:02	-1.1	8:09	6.8	6:37	7:44		6	Sun
7	Mon	12:08	6.7	4:23	7.5	8:07	-1.1	9:12	6.2	6:38	7:42		7	Mon
8	Tue	1:35	6.6	4:55	7.6	9:05	-1.0	9:58	5.3	6:40	7:40		8	Tue
9	Wed	2:56	6.7	5:23	7.6	9:55	-0.7	10:39	4.3	6:41	7:38		9	Wed
10	Thu	4:08	6.7	5:48	7.6	10:39	-0.1	11:19	3.3	6:42	7:36		10	Thu
11	Fri	5:13	6.7	6:11	7.6	11:21	0.8	11:59	2.3	6:44	7:33		11	Fri
12	Sat	6:13	6.7	6:31	7.5			12:01	1.8	6:45	7:31		12	Sat
13	Sun	7:13	6.6	6:52	7.4	12:38	1.4	12:42	2.9	6:47	7:29		13	Sun
14	Mon	8:14	6.6	7:14	7.2	1:18	0.7	1:25	4.0	6:48	7:27		14	Mon
15	Tue	9:20	6.5	7:38	6.9	1:59	0.3	2:14	5.0	6:49	7:25		15	Tue
16	Wed	10:39	6.5	8:04	6.6	2:42	0.1	3:13	5.8	6:51	7:23		16	Wed
17	Thu			12:10	6.6	3:28	0.2	4:35	6.4	6:52	7:21		17	Thu
18	Fri			1:36	6.8	4:20	0.4	6:56	6.6	6:54	7:19		18	Fri
19	Sat			2:40	7.0	5:22	0.7	8:55	6.3	6:55	7:16		19	Sat
20	Sun			3:26	7.1	6:30	0.9	9:30	6.0	6:56	7:14		20	Sun
21	Mon			4:00	7.2	7:36	0.9	9:48	5.6	6:58	7:12		21	Mon
22	Tue	12:56	5.7	4:25	7.2	8:30	0.9	10:00	5.1	6:59	7:10		22	Tue
23	Wed	2:09	5.8	4:42	7.2	9:14	0.9	10:16	4.5	7:01	7:08		23	Wed
24	Thu	3:13	6.1	4:56	7.2	9:52	1.1	10:37	3.6	7:02	7:06		24	Thu
25	Fri	4:12	6.3	5:09	7.3	10:27	1.5	11:04	2.6	7:04	7:04		25	Fri
26	Sat	5:07	6.5	5:27	7.4	11:02	2.1	11:34	1.4	7:05	7:02		26	Sat
27	Sun	6:03	6.8	5:48	7.4	11:37	2.9			7:06	7:00		27	Sun
28	Mon	6:59	7.0	6:11	7.5	12:09	0.3	12:15	3.9	7:08	6:57		28	Mon
29	Tue	7:58	7.1	6:36	7.4	12:48	-0.6	12:57	4.8	7:09	6:55		29	Tue
30	Wed	9:03	7.1	7:03	7.3	1:32	-1.3	1:43	5.7	7:11	6:53		30	Wed
Date		High Tide				Low Tide				Sun		Moon	Date
Date		AM	ft	PM	ft	AM	ft	PM	ft	Rise	Set	Moon	Date

Tidal Data Source: (9449834)

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When is the lowest tide this week in Roche Harbor, San Juan Island, WA?

The lowest tide this week in Roche Harbor, San Juan Island, WA is 0.3 ft on Monday, Sep 28 at 12:09 am.

When is the highest tide this week in Roche Harbor, San Juan Island, WA?

The highest tide this week in Roche Harbor, San Juan Island, WA is 7.4 ft on Sunday, Sep 27 at 5:48 pm — worth noting for launching your boat and being alert for possible high tide flooding.

Is this week a spring tide or neap tide in Roche Harbor, San Juan Island, WA?

Roche Harbor, San Juan Island, WA is currently in a transitional phase. Tonight's moon is 76% illuminated. Spring tides (largest swings) occur near new and full moons; neap tides (smallest swings) occur near first and third quarter moons. Tidal ranges this week are shifting between spring and neap.

What datum are Roche Harbor, San Juan Island, WA tide heights measured from?

Tide heights on this page are measured from Mean Lower Low Water (MLLW), the U.S. NOAA standard. A height of 0 ft represents the 19-year average of each day's lower low tide. Negative values indicate a "minus tide" — water levels below that long-term reference.

What factors can affect the tide predictions for Roche Harbor, San Juan Island, WA?

Tide predictions for Roche Harbor, San Juan Island, WA come from NOAA's harmonic analysis and are typically accurate within about ±10 minutes on timing and ±0.5 ft on height. Actual water levels can deviate further due to sustained winds, atmospheric pressure changes, river flow, and storm surge. During major weather events, be sure to check US Harbors weather pages for factors that could impact tidal predictions.

Which NOAA station provides tide data for Roche Harbor, San Juan Island, WA?

Tide data for Roche Harbor, San Juan Island, WA is sourced from NOAA Station #9449834. View the official NOAA station page at https://tidesandcurrents.noaa.gov/stationhome.html?id=9449834.

What time is high tide in Roche Harbor, San Juan Island, WA today?

High tides in Roche Harbor, San Juan Island, WA today: 4:00 pm (7.2 ft).

What time is low tide in Roche Harbor, San Juan Island, WA today?

Low tides in Roche Harbor, San Juan Island, WA today: 7:36 am (0.9 ft), 9:48 pm (5.6 ft).

What is the tidal range in Roche Harbor, San Juan Island, WA today?

Today's tidal range in Roche Harbor, San Juan Island, WA is 6.3 ft — the difference between the day's highest and lowest water level. This month's average daily range is about 6.9 ft, so today's swing is below-average.

What is the moon phase in Roche Harbor, San Juan Island, WA tonight?

Tonight the moon over Roche Harbor, San Juan Island, WA is Waxing Gibbous (76% illuminated). This places Roche Harbor, San Juan Island, WA in a transitional tide cycle, so tidal ranges are shifting between spring and neap this week.

What type of tides does Roche Harbor, San Juan Island, WA have — semi-diurnal, diurnal, or mixed?

Roche Harbor, San Juan Island, WA has mixed tides — two high tides and two low tides per day with noticeably different heights — common on the U.S. West Coast.

US Harbors Tidal Data

The data in our tide charts, tide tables, and tide graphs is provided by NOAA and others. These predictions are derived mathematically from numerous inputs, including data from historical tide stations and nearby locations where sensors are actively recording. As shown in the tide graph at the top of this page, “Predicted” tides (blue) are what forecasting models expect to happen. “Observed” tides (red) are those recorded by local sensors in real time, overlaid on the predictions for direct comparison. We display Observed water levels for a select group of harbors including Portland, Maine, where a physical sensor monitors water levels in real time.

LEARN MORE ABOUT OUR TIDE DATA

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