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

TIDE TIMES for Friday, July 31, 2026
The tide is currently falling in Roche Harbor, San Juan Island, WA.
Next low tide : in 6h 29m at 12:35 pm (-0.7 ft)
Next high tide : 8:05 pm (7.7 ft)
Sunset today : 8:51 pm
Sunrise tomorrow : 5:46 am
Moon phase : Waning Gibbous (95% illuminated)
Tide Station Location : Station #9449834
Common Questions About Tides

Roche Harbor, San Juan Island, WA Tides - Oct 2085

DateHigh TideLow TideSunMoonDate
AMftPMftAMftPMftRiseSet
1Mon3:136.44:107.69:221.210:081.97:136:50Full Moon1Mon
2Tue4:276.84:377.710:101.910:490.67:156:48Full Moon2Tue
3Wed5:327.25:067.810:562.811:31-0.57:166:46Full Moon3Wed
4Thu6:347.45:367.811:433.87:186:44Full Moon4Thu
5Fri7:337.66:087.612:13-1.212:314.77:196:41Waning Gibbous5Fri
6Sat8:337.66:427.312:58-1.51:255.47:206:39Waning Gibbous6Sat
7Sun9:367.67:197.01:44-1.42:276.07:226:37Waning Gibbous7Sun
8Mon10:447.58:016.52:33-1.03:456.37:236:35Third Quarter8Mon
9Tue11:557.48:526.03:26-0.45:356.27:256:33Third Quarter9Tue
10Wed12:597.44:240.37:325.87:266:31Third Quarter10Wed
11Thu1:537.45:291.08:305.27:286:29Third Quarter11Thu
12Fri2:357.36:351.79:054.57:296:27Waning Crescent12Fri
13Sat1:095.13:067.27:382.29:303.87:316:25Waning Crescent13Sat
14Sun2:415.43:287.18:312.79:493.07:326:23Waning Crescent14Sun
15Mon3:495.83:437.19:163.210:092.27:346:21Waning Crescent15Mon
16Tue4:426.23:567.19:563.710:321.47:356:20New Moon16Tue
17Wed5:286.64:157.110:334.210:570.67:376:18New Moon17Wed
18Thu6:116.94:387.211:094.811:25-0.17:386:16New Moon18Thu
19Fri6:537.25:047.211:465.311:57-0.77:406:14New Moon19Fri
20Sat7:357.45:327.112:255.87:416:12Waxing Crescent20Sat
21Sun8:227.66:007.012:33-1.11:096.27:436:10Waxing Crescent21Sun
22Mon9:137.66:286.81:13-1.31:596.67:446:08Waxing Crescent22Mon
23Tue10:097.66:586.61:58-1.33:016.77:466:07Waxing Crescent23Tue
24Wed11:087.67:446.32:48-1.04:216.67:486:05First Quarter24Wed
25Thu12:057.63:43-0.55:536.27:496:03First Quarter25Thu
26Fri12:527.74:430.17:075.37:516:01First Quarter26Fri
27Sat1:327.75:480.97:554.17:525:59First Quarter27Sat
28Sun12:415.32:067.86:531.78:362.87:545:58Waxing Gibbous28Sun
29Mon2:245.62:377.97:552.79:141.37:555:56Waxing Gibbous29Mon
30Tue3:516.23:067.98:523.69:52-0.17:575:54Waxing Gibbous30Tue
31Wed5:006.93:368.09:454.410:30-1.27:595:53Full Moon31Wed
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 4:20 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 95% 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 Gibbous (95% 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