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

TIDE TIMES for Thursday, July 23, 2026
The tide is currently falling in Roche Harbor, San Juan Island, WA.
Next low tide : in 6h 24m at 7:27 am (0.2 ft)
Next high tide : 4:07 pm (6.4 ft)
Sunset today : 9:02 pm
Sunrise tomorrow : 5:35 am
Moon phase : Waxing Gibbous (72% illuminated)
Tide Station Location : Station #9449834
Common Questions About Tides

Roche Harbor, San Juan Island, WA Tides - May 1987

DateHigh TideLow TideSunMoonDate
AMftPMftAMftPMftRiseSet
1Fri6:016.710:017.61:526.61:36-1.45:528:26Waxing Crescent1Fri
2Sat6:246.410:587.63:056.82:18-1.05:518:28Waxing Crescent2Sat
3Sun6:186.111:577.45:296.73:05-0.55:498:29Waxing Crescent3Sun
4Mon3:560.15:478:30First Quarter4Mon
5Tue12:507.44:530.75:468:32First Quarter5Tue
6Wed1:327.310:16 AM4.99:055.45:521.25:448:33First Quarter6Wed
7Thu2:027.311:57 AM4.79:084.76:501.85:438:35First Quarter7Thu
8Fri2:227.21:374.79:123.87:432.45:418:36Waxing Gibbous8Fri
9Sat2:387.23:105.19:242.88:323.15:408:38Waxing Gibbous9Sat
10Sun2:567.34:245.79:441.59:183.95:388:39Waxing Gibbous10Sun
11Mon3:167.45:256.410:100.210:024.75:378:40Waxing Gibbous11Mon
12Tue3:397.56:197.110:42-1.110:475.55:358:42Full Moon12Tue
13Wed4:047.57:127.611:18-2.211:346.25:348:43Full Moon13Wed
14Thu4:317.68:047.911:58-3.05:328:44Full Moon14Thu
15Fri5:007.68:598.112:246.812:43-3.35:318:46Waning Gibbous15Fri
16Sat5:337.49:578.21:217.11:31-3.25:308:47Waning Gibbous16Sat
17Sun6:147.110:558.12:317.22:24-2.75:298:48Waning Gibbous17Sun
18Mon7:096.611:498.14:017.03:20-1.95:278:50Third Quarter18Mon
19Tue8:355.86:126.34:19-0.95:268:51Third Quarter19Tue
20Wed12:368.010:17 AM5.17:335.25:200.35:258:52Third Quarter20Wed
21Thu1:168.012:144.68:163.96:211.55:248:53Third Quarter21Thu
22Fri1:507.92:204.88:512.67:222.85:238:55Waning Crescent22Fri
23Sat2:197.83:565.49:221.38:214.05:228:56Waning Crescent23Sat
24Sun2:437.75:066.29:510.19:175.05:218:57Waning Crescent24Sun
25Mon3:037.56:036.910:20-0.910:115.95:208:58New Moon25Mon
26Tue3:247.46:527.510:49-1.611:046.55:198:59New Moon26Tue
27Wed3:457.27:367.811:20-1.911:586.95:189:00New Moon27Wed
28Thu4:087.08:188.011:53-2.15:179:02New Moon28Thu
29Fri4:346.89:008.012:557.012:29-1.95:169:03Waxing Crescent29Fri
30Sat5:026.69:417.92:007.11:09-1.75:159:04Waxing Crescent30Sat
31Sun5:296.310:227.83:286.91:50-1.25:159:05Waxing Crescent31Sun
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 11:47 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 transitional phase. Tonight's moon is 72% 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 shifting between spring and neap.

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 Waxing Gibbous (72% illuminated). This places Roche Harbor, San Juan Island, WA in a transitional tide cycle, so tidal ranges are shifting between spring and neap 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