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

TIDE TIMES for Friday, July 10, 2026
The tide is currently falling in Roche Harbor, San Juan Island, WA.
Next low tide : in 1h 48m at 7:56 am (-1.3 ft)
Next high tide : 4:38 pm (6.5 ft)
Sunset today : 9:14 pm
Sunrise tomorrow : 5:21 am
Moon phase : Waning Crescent (18% illuminated)
Tide Station Location : Station #9449834
Common Questions About Tides

Roche Harbor, San Juan Island, WA Tides - Sep 1998

DateHigh TideLow TideSunMoonDate
AMftPMftAMftPMftRiseSet
1Tue3:466.57:220.88:185.86:307:55Waxing Gibbous1Tue
2Wed12:456.34:216.88:140.39:055.66:317:53Waxing Gibbous2Wed
3Thu1:456.54:507.09:01-0.19:435.26:327:51Waxing Gibbous3Thu
4Fri2:446.75:177.39:46-0.410:204.66:347:48Waxing Gibbous4Fri
5Sat3:426.95:447.410:28-0.510:593.96:357:46Full Moon5Sat
6Sun4:407.16:127.611:11-0.311:403.06:367:44Full Moon6Sun
7Mon5:377.16:437.711:540.26:387:42Full Moon7Mon
8Tue6:367.17:157.712:262.212:381.06:397:40Waning Gibbous8Tue
9Wed7:376.97:507.71:141.41:241.96:417:38Waning Gibbous9Wed
10Thu8:436.78:287.52:060.72:143.06:427:36Waning Gibbous10Thu
11Fri9:586.49:097.33:010.23:104.06:437:34Third Quarter11Fri
12Sat11:286.49:567.04:000.04:184.96:457:32Third Quarter12Sat
13Sun1:016.55:020.05:415.56:467:30Third Quarter13Sun
14Mon2:176.96:090.07:195.66:487:28Third Quarter14Mon
15Tue3:167.27:160.28:445.36:497:25Waning Crescent15Tue
16Wed1:136.14:037.48:180.39:384.86:507:23Waning Crescent16Wed
17Thu2:286.14:427.59:110.510:154.36:527:21Waning Crescent17Thu
18Fri3:346.35:147.49:560.810:463.86:537:19New Moon18Fri
19Sat4:296.45:417.310:371.111:153.26:557:17New Moon19Sat
20Sun5:166.56:027.211:141.611:452.76:567:15New Moon20Sun
21Mon6:006.66:217.111:512.16:587:13New Moon21Mon
22Tue6:436.66:417.012:172.212:282.76:597:11Waxing Crescent22Tue
23Wed7:276.67:056.912:511.81:083.47:007:08Waxing Crescent23Wed
24Thu8:136.67:346.81:271.41:494.07:027:06Waxing Crescent24Thu
25Fri9:046.58:056.62:051.22:364.67:037:04Waxing Crescent25Fri
26Sat10:036.48:406.32:461.03:305.27:057:02Waxing Crescent26Sat
27Sun11:166.49:206.13:321.04:375.67:067:00First Quarter27Sun
28Mon12:406.54:241.06:005.87:076:58First Quarter28Mon
29Tue1:506.75:231.07:205.87:096:56First Quarter29Tue
30Wed2:396.96:261.08:135.47:106:54Waxing Gibbous30Wed
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 12:17 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 18% 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 Waning Crescent (18% 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