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

TIDE TIMES for Thursday, July 30, 2026
The tide is currently rising in Roche Harbor, San Juan Island, WA.
Next low tide (tomorrow) : 12:53 am (5.6 ft)
Next high tide : in 6h 03m at 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 - Jul 1977

DateHigh TideLow TideSunMoonDate
AMftPMftAMftPMftRiseSet
1Fri4:077.77:168.111:23-2.911:555.75:149:18Full Moon1Fri
2Sat5:037.57:568.312:09-2.65:159:18Waning Gibbous2Sat
3Sun5:597.08:368.312:555.412:55-2.05:159:17Waning Gibbous3Sun
4Mon6:576.59:168.21:594.91:42-1.15:169:17Waning Gibbous4Mon
5Tue7:595.89:548.13:064.32:290.05:179:17Waning Gibbous5Tue
6Wed9:075.210:317.94:143.73:161.25:189:16Third Quarter6Wed
7Thu10:324.711:067.75:192.94:062.55:189:16Third Quarter7Thu
8Fri12:324.66:192.25:013.75:199:15Third Quarter8Fri
9Sat2:265.17:131.56:064.85:209:15Third Quarter9Sat
10Sun12:147.33:465.78:000.97:205.55:219:14Waning Crescent10Sun
11Mon12:507.14:436.38:410.48:326.05:229:13Waning Crescent11Mon
12Tue1:287.05:266.89:17-0.19:326.25:239:13Waning Crescent12Tue
13Wed2:086.96:017.19:52-0.410:206.25:249:12Waning Crescent13Wed
14Thu2:516.86:317.310:25-0.711:006.25:259:11New Moon14Thu
15Fri3:356.86:587.410:59-0.911:376.05:269:10New Moon15Fri
16Sat4:206.77:227.611:33-1.05:279:09New Moon16Sat
17Sun5:056.67:467.712:155.812:08-0.95:289:08New Moon17Sun
18Mon5:526.48:117.812:555.412:43-0.75:299:07Waxing Crescent18Mon
19Tue6:416.28:397.81:395.01:21-0.35:309:06Waxing Crescent19Tue
20Wed7:355.89:097.92:264.31:590.45:329:05Waxing Crescent20Wed
21Thu8:365.49:427.93:163.62:401.35:339:04Waxing Crescent21Thu
22Fri9:475.010:167.84:082.83:242.35:349:03First Quarter22Fri
23Sat11:144.910:537.85:031.84:133.45:359:02First Quarter23Sat
24Sun1:075.06:000.95:144.55:369:01First Quarter24Sun
25Mon2:515.66:570.06:285.35:389:00Waxing Gibbous25Mon
26Tue12:207.73:596.37:53-0.97:455.85:398:58Waxing Gibbous26Tue
27Wed1:117.64:507.08:45-1.58:555.95:408:57Waxing Gibbous27Wed
28Thu2:077.65:327.49:35-2.09:555.75:418:56Waxing Gibbous28Thu
29Fri3:077.56:117.710:22-2.110:495.35:438:54Full Moon29Fri
30Sat4:067.46:477.911:08-1.911:424.95:448:53Full Moon30Sat
31Sun5:047.27:228.011:52-1.55:458:52Full Moon31Sun
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 10:19 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