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 5h 50m 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 - Aug 2083

DateHigh TideLow TideSunMoonDate
AMftPMftAMftPMftRiseSet
1Sun7:146.18:397.81:563.91:340.65:478:50Waning Gibbous1Sun
2Mon8:195.69:037.72:483.12:151.95:498:48Waning Gibbous2Mon
3Tue9:355.29:277.43:402.32:573.25:508:47Third Quarter3Tue
4Wed11:205.19:527.24:301.63:424.55:518:45Third Quarter4Wed
5Thu1:365.45:211.14:395.65:538:44Third Quarter5Thu
6Fri3:176.16:140.76:076.45:548:42Third Quarter6Fri
7Sat4:156.67:090.47:586.85:558:40Waning Crescent7Sat
8Sun4:567.08:020.19:266.85:578:39Waning Crescent8Sun
9Mon12:296.55:287.38:51-0.210:096.75:588:37Waning Crescent9Mon
10Tue1:296.55:547.49:34-0.510:346.56:008:35Waning Crescent10Tue
11Wed2:286.66:167.410:13-0.810:586.26:018:34New Moon11Wed
12Thu3:246.76:357.510:49-0.911:265.76:028:32New Moon12Thu
13Fri4:176.76:527.511:23-0.811:595.06:048:30New Moon13Fri
14Sat5:116.67:107.611:58-0.46:058:28New Moon14Sat
15Sun6:066.57:317.712:374.112:330.26:078:27Waxing Crescent15Sun
16Mon7:046.27:557.71:183.21:091.26:088:25Waxing Crescent16Mon
17Tue8:086.08:217.72:032.11:482.36:098:23Waxing Crescent17Tue
18Wed9:215.78:497.72:511.12:283.66:118:21Waxing Crescent18Wed
19Thu10:515.69:207.63:430.23:134.86:128:19First Quarter19Thu
20Fri12:525.84:39-0.44:105.96:148:17First Quarter20Fri
21Sat2:366.45:41-0.95:346.76:158:16First Quarter21Sat
22Sun3:406.96:47-1.17:166.96:168:14Waxing Gibbous22Sun
23Mon4:247.37:52-1.38:406.76:188:12Waxing Gibbous23Mon
24Tue12:597.05:017.68:52-1.49:406.16:198:10Waxing Gibbous24Tue
25Wed2:166.95:337.79:44-1.310:275.46:208:08Full Moon25Wed
26Thu3:286.86:017.710:29-0.911:094.56:228:06Full Moon26Thu
27Fri4:336.86:277.711:11-0.311:513.76:238:04Full Moon27Fri
28Sat5:336.76:507.611:500.56:258:02Full Moon28Sat
29Sun6:316.57:107.512:322.812:291.56:268:00Waning Gibbous29Sun
30Mon7:296.37:317.31:132.01:092.66:277:58Waning Gibbous30Mon
31Tue8:296.17:537.21:551.41:503.76:297:56Waning Gibbous31Tue
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 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