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 06m 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 - Sep 2084

DateHigh TideLow TideSunMoonDate
AMftPMftAMftPMftRiseSet
1Fri5:536.46:367.312:013.212:001.66:317:52New Moon1Fri
2Sat6:446.46:597.412:342.412:342.36:337:50Waxing Crescent2Sat
3Sun7:386.37:247.31:101.51:093.26:347:48Waxing Crescent3Sun
4Mon8:386.27:517.31:500.71:474.16:367:46Waxing Crescent4Mon
5Tue9:476.28:197.22:350.12:305.06:377:44Waxing Crescent5Tue
6Wed11:166.28:517.13:26-0.33:215.96:387:42First Quarter6Wed
7Thu1:026.44:23-0.64:326.56:407:40First Quarter7Thu
8Fri2:236.75:27-0.76:096.76:417:38First Quarter8Fri
9Sat3:157.06:36-0.77:406.46:427:36Waxing Gibbous9Sat
10Sun3:547.37:43-0.78:455.76:447:34Waxing Gibbous10Sun
11Mon1:236.64:267.48:42-0.69:344.86:457:31Waxing Gibbous11Mon
12Tue2:446.64:547.69:34-0.310:183.76:477:29Full Moon12Tue
13Wed3:586.75:207.610:200.310:592.66:487:27Full Moon13Wed
14Thu5:066.95:457.711:031.211:411.56:497:25Full Moon14Thu
15Fri6:086.96:107.611:462.26:517:23Full Moon15Fri
16Sat7:086.96:357.512:220.612:303.26:527:21Waning Gibbous16Sat
17Sun8:096.97:017.31:040.01:164.26:547:19Waning Gibbous17Sun
18Mon9:146.97:307.01:47-0.32:085.16:557:17Waning Gibbous18Mon
19Tue10:266.88:016.72:33-0.33:095.86:567:14Waning Gibbous19Tue
20Wed11:496.88:376.33:22-0.14:306.36:587:12Third Quarter20Wed
21Thu1:106.94:160.36:346.36:597:10Third Quarter21Thu
22Fri2:147.05:180.78:236.07:017:08Third Quarter22Fri
23Sat3:027.16:261.09:085.67:027:06Third Quarter23Sat
24Sun3:377.17:311.29:335.27:047:04Waning Crescent24Sun
25Mon1:145.54:037.18:251.49:514.67:057:02Waning Crescent25Mon
26Tue2:295.74:207.19:101.610:093.97:067:00Waning Crescent26Tue
27Wed3:325.94:337.19:481.910:303.07:086:58Waning Crescent27Wed
28Thu4:276.24:477.210:232.310:552.17:096:55New Moon28Thu
29Fri5:186.55:067.210:572.911:241.17:116:53New Moon29Fri
30Sat6:086.85:297.311:323.611:570.17:126:51New Moon30Sat
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