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 6h 55m 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 - Jul 1978

DateHigh TideLow TideSunMoonDate
AMftPMftAMftPMftRiseSet
1Sat1:437.35:036.69:18-0.29:075.85:149:18Waning Crescent1Sat
2Sun2:197.15:497.19:52-0.610:046.15:149:18Waning Crescent2Sun
3Mon2:557.06:277.410:25-0.910:536.25:159:17New Moon3Mon
4Tue3:336.97:027.610:57-1.011:376.25:169:17New Moon4Tue
5Wed4:126.77:327.711:31-1.15:179:17New Moon5Wed
6Thu4:536.68:007.712:206.012:06-1.05:179:16New Moon6Thu
7Fri5:366.48:267.71:035.912:41-0.85:189:16Waxing Crescent7Fri
8Sat6:216.28:527.71:495.61:18-0.45:199:15Waxing Crescent8Sat
9Sun7:095.89:197.82:375.21:540.15:209:15Waxing Crescent9Sun
10Mon8:015.49:497.83:264.72:320.85:219:14Waxing Crescent10Mon
11Tue9:015.010:207.74:154.13:111.65:229:13First Quarter11Tue
12Wed10:124.710:547.75:043.33:532.55:239:13First Quarter12Wed
13Thu11:394.511:297.65:532.54:413.55:249:12First Quarter13Thu
14Fri1:344.86:421.55:424.45:259:11First Quarter14Fri
15Sat12:077.63:165.47:300.46:545.25:269:10Waxing Gibbous15Sat
16Sun12:487.64:196.28:17-0.68:055.75:279:09Waxing Gibbous16Sun
17Mon1:337.75:076.99:04-1.59:085.95:289:09Waxing Gibbous17Mon
18Tue2:237.75:497.49:51-2.210:055.85:299:08Full Moon18Tue
19Wed3:187.86:287.810:37-2.611:005.65:309:07Full Moon19Wed
20Thu4:157.77:068.011:23-2.611:555.25:319:06Full Moon20Thu
21Fri5:137.47:448.212:10-2.35:329:04Waning Gibbous21Fri
22Sat6:137.08:228.212:524.712:57-1.65:349:03Waning Gibbous22Sat
23Sun7:156.59:008.21:534.11:44-0.65:359:02Waning Gibbous23Sun
24Mon8:205.99:388.12:563.42:320.65:369:01Waning Gibbous24Mon
25Tue9:355.410:167.94:002.73:221.95:379:00Third Quarter25Tue
26Wed11:105.010:557.65:042.04:163.25:398:59Third Quarter26Wed
27Thu1:065.16:071.45:194.35:408:57Third Quarter27Thu
28Fri2:435.77:060.96:345.25:418:56Third Quarter28Fri
29Sat12:177.13:536.37:590.47:545.75:428:55Waning Crescent29Sat
30Sun1:016.94:456.88:450.19:065.95:448:53Waning Crescent30Sun
31Mon1:476.75:267.19:26-0.210:015.95:458:52Waning Crescent31Mon
DateHigh TideLow TideSunMoonDate
AMftPMftAMftPMftRiseSet
Tidal Data Source: (9449834)

Common Questions About Roche Harbor, San Juan Island, WA Tides

Show All
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