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 3h 07m 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 - Apr 1977

DateHigh TideLow TideSunMoonDate
AMftPMftAMftPMftRiseSet
1Fri3:027.12:316.38:493.58:441.55:496:43Waxing Gibbous1Fri
2Sat3:277.33:326.69:222.59:261.85:476:44Full Moon2Sat
3Sun3:557.54:307.09:591.410:092.35:456:46Full Moon3Sun
4Mon4:257.75:267.210:390.410:533.05:436:47Full Moon4Mon
5Tue4:587.76:237.411:22-0.511:393.75:416:49Waning Gibbous5Tue
6Wed5:347.77:227.412:08-1.15:396:50Waning Gibbous6Wed
7Thu6:137.68:257.312:304.412:57-1.35:376:52Waning Gibbous7Thu
8Fri6:557.39:347.31:275.01:50-1.25:356:53Waning Gibbous8Fri
9Sat7:436.910:487.22:345.42:47-0.85:336:55Third Quarter9Sat
10Sun8:416.411:587.33:555.63:49-0.25:316:56Third Quarter10Sun
11Mon9:535.95:325.34:560.55:296:57Third Quarter11Mon
12Tue12:577.411:22 AM5.57:024.76:041.15:276:59Waning Crescent12Tue
13Wed1:477.41:015.58:013.97:081.75:257:00Waning Crescent13Wed
14Thu2:277.52:255.88:413.18:032.25:237:02Waning Crescent14Thu
15Fri3:017.43:306.19:132.38:512.85:217:03Waning Crescent15Fri
16Sat3:287.34:246.59:421.69:343.35:197:05New Moon16Sat
17Sun3:517.25:116.710:101.010:153.95:177:06New Moon17Sun
18Mon4:117.15:547.010:400.410:554.45:157:08New Moon18Mon
19Tue4:347.06:357.111:120.111:374.85:137:09New Moon19Tue
20Wed5:016.97:167.211:46-0.25:117:11Waxing Crescent20Wed
21Thu5:316.77:587.212:235.212:22-0.25:097:12Waxing Crescent21Thu
22Fri6:056.58:447.11:125.51:01-0.15:077:14Waxing Crescent22Fri
23Sat6:416.29:347.12:085.71:440.15:067:15Waxing Crescent23Sat
24Sun8:215.911:277.04:145.83:290.46:048:17First Quarter24Sun
25Mon9:115.65:315.74:200.86:028:18First Quarter25Mon
26Tue12:187.010:16 AM5.36:475.45:161.26:008:19First Quarter26Tue
27Wed1:037.011:34 AM5.17:384.86:161.65:588:21First Quarter27Wed
28Thu1:417.112:595.18:134.07:162.05:578:22Waxing Gibbous28Thu
29Fri2:157.22:245.48:453.08:122.45:558:24Waxing Gibbous29Fri
30Sat2:477.33:405.99:181.89:042.95:538:25Waxing Gibbous30Sat
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