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

TIDE TIMES for Thursday, July 30, 2026
The tide is currently falling in Roche Harbor, San Juan Island, WA.
Next low tide : in 5h 04m at 12:01 pm (-1.0 ft)
Next high tide : 7:46 pm (7.7 ft)
Sunset today : 8:53 pm
Sunrise tomorrow : 5:44 am
Moon phase : Full Moon (99% illuminated)
Tide Station Location : Station #9449834
Common Questions About Tides

Roche Harbor, San Juan Island, WA Tides - Sep 2083

DateHigh TideLow TideSunMoonDate
AMftPMftAMftPMftRiseSet
1Wed9:396.08:176.92:370.92:364.76:307:54Waning Gibbous1Wed
2Thu11:086.08:446.73:220.73:305.66:327:52Third Quarter2Thu
3Fri12:586.24:110.64:466.36:337:50Third Quarter3Fri
4Sat2:266.55:060.76:426.66:347:48Third Quarter4Sat
5Sun3:246.86:090.78:526.56:367:46Third Quarter5Sun
6Mon4:047.07:130.69:346.26:377:43Waning Crescent6Mon
7Tue12:116.04:337.18:110.59:505.96:397:41Waning Crescent7Tue
8Wed1:236.04:547.19:000.310:055.56:407:39Waning Crescent8Wed
9Thu2:296.25:117.29:410.210:264.86:417:37Waning Crescent9Thu
10Fri3:306.45:267.310:180.310:533.96:437:35New Moon10Fri
11Sat4:286.65:427.410:530.711:252.86:447:33New Moon11Sat
12Sun5:256.76:027.511:291.46:467:31New Moon12Sun
13Mon6:236.86:267.612:011.712:072.36:477:29Waxing Crescent13Mon
14Tue7:236.86:527.612:410.612:473.36:487:27Waxing Crescent14Tue
15Wed8:276.87:217.61:24-0.31:304.46:507:25Waxing Crescent15Wed
16Thu9:406.77:527.42:12-0.92:185.46:517:22Waxing Crescent16Thu
17Fri11:076.78:287.23:05-1.23:176.26:537:20First Quarter17Fri
18Sat12:426.94:03-1.24:386.76:547:18First Quarter18Sat
19Sun1:597.15:09-0.96:286.76:557:16First Quarter19Sun
20Mon2:557.36:20-0.68:146.26:577:14Waxing Gibbous20Mon
21Tue3:377.57:30-0.29:115.46:587:12Waxing Gibbous21Tue
22Wed1:246.14:127.68:320.19:494.57:007:10Waxing Gibbous22Wed
23Thu2:506.14:417.69:240.610:233.57:017:08Waxing Gibbous23Thu
24Fri4:046.35:057.510:081.310:552.67:027:06Full Moon24Fri
25Sat5:066.55:257.410:482.111:271.67:047:03Full Moon25Sat
26Sun6:026.75:427.311:272.97:057:01Full Moon26Sun
27Mon6:556.86:007.212:000.812:073.87:076:59Full Moon27Mon
28Tue7:466.96:217.012:330.212:494.77:086:57Waning Gibbous28Tue
29Wed8:407.06:446.81:09-0.11:365.47:106:55Waning Gibbous29Wed
30Thu9:387.07:096.61:46-0.22:306.07:116:53Waning Gibbous30Thu
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 3:53 pm — 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 spring phase. Tonight's moon is 99% 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 near their weekly maximum.

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 Full Moon (99% illuminated). This places Roche Harbor, San Juan Island, WA in a spring tide cycle, so tidal ranges are near their weekly maximum 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