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

TIDE TIMES for Wednesday, July 22, 2026
The tide is currently rising in Roche Harbor, San Juan Island, WA.
Next low tide (tomorrow) : 7:27 am (0.2 ft)
Next high tide : in 5h 18m at 11:18 pm (7.2 ft)
Sunset today : 9:03 pm
Sunrise tomorrow : 5:34 am
Moon phase : First Quarter (63% illuminated)
Tide Station Location : Station #9449834
Common Questions About Tides

Roche Harbor, San Juan Island, WA Tides - Dec 1987

DateHigh TideLow TideSunMoonDate
AMftPMftAMftPMftRiseSet
1Tue2:355.71:068.26:464.78:260.17:434:19Waxing Gibbous1Tue
2Wed3:506.61:308.17:485.88:57-0.97:444:19Waxing Gibbous2Wed
3Thu4:487.51:537.98:496.69:29-1.67:454:18Full Moon3Thu
4Fri5:378.12:187.79:467.210:01-2.07:474:18Full Moon4Fri
5Sat6:218.52:437.510:437.510:36-2.17:484:18Full Moon5Sat
6Sun7:028.73:107.311:427.711:12-1.97:494:17Full Moon6Sun
7Mon7:428.73:397.012:477.67:504:17Waning Gibbous7Mon
8Tue8:228.64:096.72:207.47:514:17Waning Gibbous8Tue
9Wed9:018.512:33-1.07:524:17Waning Gibbous9Wed
10Thu9:388.31:15-0.47:534:17Waning Gibbous10Thu
11Fri10:098.27:155.31:580.46:095.87:544:16Third Quarter11Fri
12Sat10:358.18:484.82:411.26:275.07:554:16Third Quarter12Sat
13Sun10:588.110:334.43:232.26:424.07:564:17Third Quarter13Sun
14Mon11:218.04:093.36:592.97:574:17Third Quarter14Mon
15Tue12:594.711:45 AM8.05:024.57:211.77:584:17Waning Crescent15Tue
16Wed2:545.512:098.06:065.67:480.47:584:17Waning Crescent16Wed
17Thu3:576.512:348.07:126.58:20-0.87:594:17Waning Crescent17Thu
18Fri4:437.31:018.18:137.28:55-1.98:004:18Waning Crescent18Fri
19Sat5:238.01:318.29:077.79:35-2.78:004:18New Moon19Sat
20Sun6:038.52:088.29:587.910:17-3.28:014:18New Moon20Sun
21Mon6:438.82:558.210:508.011:03-3.38:024:19New Moon21Mon
22Tue7:248.93:528.011:467.811:51-3.08:024:19Waxing Crescent22Tue
23Wed8:048.94:567.512:517.48:034:20Waxing Crescent23Wed
24Thu8:448.96:076.812:40-2.32:066.78:034:20Waxing Crescent24Thu
25Fri9:228.87:266.01:28-1.23:265.78:034:21First Quarter25Fri
26Sat9:578.79:005.12:170.24:424.48:044:22First Quarter26Sat
27Sun10:308.711:094.83:051.85:442.98:044:22First Quarter27Sun
28Mon11:018.53:573.56:351.58:044:23First Quarter28Mon
29Tue1:325.311:30 AM8.34:585.17:190.38:044:24Waxing Gibbous29Tue
30Wed3:086.411:58 AM8.16:156.57:57-0.68:044:25Waxing Gibbous30Wed
31Thu4:107.412:277.97:407.38:30-1.28:044:26Waxing Gibbous31Thu
DateHigh TideLow TideSunMoonDate
AMftPMftAMftPMftRiseSet
Tidal Data Source: (9449834)

Common Questions About Roche Harbor, San Juan Island, WA Tides

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What time does the tide turn (slack tide) in Roche Harbor, San Juan Island, WA today?

Slack tide in Roche Harbor, San Juan Island, WA is approximately 3:22 am — midway between the next high and low tide, when tidal current is weakest. This is the preferred window for boat crossings, underwater visibility, and fishing in areas with strong currents.

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 63% 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 is the moon phase in Roche Harbor, San Juan Island, WA tonight?

Tonight the moon over Roche Harbor, San Juan Island, WA is First Quarter (63% 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.

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