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

TIDE TIMES for Friday, July 31, 2026
The tide is currently rising in Roche Harbor, San Juan Island, WA.
Next low tide (tomorrow) : 1:32 am (5.0 ft)
Next high tide : in 6h 34m at 8:05 pm (7.7 ft)
Sunset today : 8:51 pm
Sunrise tomorrow : 5:46 am
Moon phase : Waning Gibbous (95% illuminated)
Tide Station Location : Station #9449834
Common Questions About Tides

Roche Harbor, San Juan Island, WA Tides - May 2086

DateHigh TideLow TideSunMoonDate
AMftPMftAMftPMftRiseSet
1Wed5:536.88:577.51:026.01:00-1.35:518:28Waning Gibbous1Wed
2Thu6:266.79:447.51:506.31:42-1.45:498:29Waning Gibbous2Thu
3Fri7:026.410:347.52:466.32:27-1.25:478:31Waning Gibbous3Fri
4Sat7:466.111:237.53:526.23:17-0.85:468:32Third Quarter4Sat
5Sun8:535.75:065.94:10-0.25:448:33Third Quarter5Sun
6Mon12:097.510:19 AM5.36:175.15:080.65:438:35Third Quarter6Mon
7Tue12:497.511:55 AM5.07:154.06:101.55:418:36Third Quarter7Tue
8Wed1:257.61:395.18:022.77:132.45:408:38Waning Crescent8Wed
9Thu1:597.73:175.68:441.38:143.45:388:39Waning Crescent9Thu
10Fri2:337.74:346.49:25-0.19:124.25:378:40Waning Crescent10Fri
11Sat3:077.85:367.110:06-1.310:075.05:358:42New Moon11Sat
12Sun3:427.86:307.610:47-2.211:005.55:348:43New Moon12Sun
13Mon4:207.77:218.011:29-2.711:545.95:338:45New Moon13Mon
14Tue5:007.58:118.112:13-2.75:318:46Waxing Crescent14Tue
15Wed5:437.29:008.112:526.112:57-2.45:308:47Waxing Crescent15Wed
16Thu6:286.89:498.01:576.21:44-1.85:298:49Waxing Crescent16Thu
17Fri7:176.210:387.93:136.02:31-1.05:288:50Waxing Crescent17Fri
18Sat8:125.611:247.74:405.63:21-0.15:268:51First Quarter18Sat
19Sun9:185.06:075.04:120.95:258:52First Quarter19Sun
20Mon12:057.510:41 AM4.67:124.25:062.05:248:54First Quarter20Mon
21Tue12:407.412:414.47:573.46:033.05:238:55First Quarter21Tue
22Wed1:077.22:444.78:302.57:043.95:228:56Waxing Gibbous22Wed
23Thu1:307.14:025.48:571.78:054.75:218:57Waxing Gibbous23Thu
24Fri1:537.14:596.09:230.89:005.35:208:58Waxing Gibbous24Fri
25Sat2:207.15:436.69:490.09:495.85:199:00Waxing Gibbous25Sat
26Sun2:497.16:227.010:17-0.710:346.25:189:01Full Moon26Sun
27Mon3:217.16:577.410:48-1.311:166.45:179:02Full Moon27Mon
28Tue3:567.17:327.611:21-1.711:596.65:169:03Full Moon28Tue
29Wed4:327.08:077.811:58-2.05:169:04Full Moon29Wed
30Thu5:126.98:447.912:446.612:38-2.15:159:05Waning Gibbous30Thu
31Fri5:556.79:228.01:366.51:20-2.05:149:06Waning Gibbous31Fri
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 10:48 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 95% 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 Waning Gibbous (95% 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