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 3h 07m at 12:53 am (5.6 ft)
Next high tide : 5:34 am (6.5 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 - Nov 1976

DateHigh TideLow TideSunMoonDate
AMftPMftAMftPMftRiseSet
1Mon12:245.11:197.76:002.78:072.86:594:52Waxing Gibbous1Mon
2Tue1:595.51:517.57:033.48:362.07:014:51Waxing Gibbous2Tue
3Wed3:086.02:167.47:584.19:011.37:024:49Waxing Gibbous3Wed
4Thu4:026.62:367.38:464.79:260.67:044:47Waxing Gibbous4Thu
5Fri4:487.02:567.29:305.29:520.17:064:46Full Moon5Fri
6Sat5:297.33:207.110:115.610:21-0.37:074:44Full Moon6Sat
7Sun6:067.63:487.110:515.910:51-0.67:094:43Full Moon7Sun
8Mon6:427.74:196.911:346.211:24-0.77:104:42Full Moon8Mon
9Tue7:187.84:536.712:206.37:124:40Waning Gibbous9Tue
10Wed7:567.95:276.512:00-0.71:136.47:134:39Waning Gibbous10Wed
11Thu8:367.96:046.212:39-0.52:156.47:154:37Waning Gibbous11Thu
12Fri9:197.96:505.81:21-0.23:276.27:174:36Waning Gibbous12Fri
13Sat10:027.97:585.42:060.34:425.77:184:35Third Quarter13Sat
14Sun10:437.89:245.02:560.95:375.07:204:34Third Quarter14Sun
15Mon11:227.910:584.93:511.66:174.17:214:32Third Quarter15Mon
16Tue11:587.94:522.46:542.97:234:31Waning Crescent16Tue
17Wed12:395.212:348.05:563.37:311.57:244:30Waning Crescent17Wed
18Thu2:125.81:098.16:594.18:100.17:264:29Waning Crescent18Thu
19Fri3:236.61:468.27:584.88:50-1.17:274:28Waning Crescent19Fri
20Sat4:227.42:248.38:535.39:32-2.17:294:27New Moon20Sat
21Sun5:148.03:058.39:465.810:15-2.77:304:26New Moon21Sun
22Mon6:048.43:508.110:406.110:59-2.87:324:25New Moon22Mon
23Tue6:538.64:377.811:386.311:46-2.57:334:24Waxing Crescent23Tue
24Wed7:428.75:277.312:426.37:354:24Waxing Crescent24Wed
25Thu8:318.76:236.712:34-1.91:566.07:364:23Waxing Crescent25Thu
26Fri9:208.67:256.01:23-0.93:225.57:374:22First Quarter26Fri
27Sat10:088.48:395.32:140.24:514.87:394:21First Quarter27Sat
28Sun10:538.310:194.83:071.46:023.97:404:21First Quarter28Sun
29Mon11:338.14:042.76:543.07:414:20First Quarter29Mon
30Tue12:324.912:077.95:073.87:332.17:434:19Waxing Gibbous30Tue
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 3:13 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 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