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

TIDE TIMES for Friday, July 17, 2026
The tide is currently rising in Roche Harbor, San Juan Island, WA.
Next low tide : 1:31 pm (-1.3 ft)
Next high tide : in 1h 54m at 6:35 am (6.6 ft)
Sunset today : 9:08 pm
Sunrise tomorrow : 5:28 am
Moon phase : Waxing Crescent (15% illuminated)
Tide Station Location : Station #9449834
Common Questions About Tides

Roche Harbor, San Juan Island, WA Tides - Dec 2069

DateHigh TideLow TideSunMoonDate
AMftPMftAMftPMftRiseSet
1Sun7:448.85:337.212:506.37:444:19Waning Gibbous1Sun
2Mon8:318.76:306.512:38-1.72:055.97:454:18Waning Gibbous2Mon
3Tue9:178.67:365.81:27-0.73:305.37:474:18Third Quarter3Tue
4Wed10:018.58:555.12:170.54:554.57:484:17Third Quarter4Wed
5Thu10:428.310:474.83:091.86:023.67:494:17Third Quarter5Thu
6Fri11:198.14:053.16:522.77:504:17Third Quarter6Fri
7Sat12:575.011:52 AM7.95:084.37:311.97:514:17Waning Crescent7Sat
8Sun2:285.712:217.76:175.28:021.17:524:17Waning Crescent8Sun
9Mon3:326.412:497.67:255.98:300.57:534:16Waning Crescent9Mon
10Tue4:217.11:197.58:256.48:58-0.17:544:16Waning Crescent10Tue
11Wed5:017.61:527.49:166.79:27-0.57:554:16New Moon11Wed
12Thu5:377.92:287.410:016.89:57-0.87:564:16New Moon12Thu
13Fri6:088.13:057.310:436.910:29-1.07:574:17New Moon13Fri
14Sat6:388.23:457.111:256.911:03-1.07:584:17New Moon14Sat
15Sun7:078.34:276.912:096.77:584:17Waxing Crescent15Sun
16Mon7:368.45:116.612:586.57:594:17Waxing Crescent16Mon
17Tue8:068.56:006.312:17-0.61:506.18:004:17Waxing Crescent17Tue
18Wed8:388.56:585.812:56-0.22:455.58:004:18Waxing Crescent18Wed
19Thu9:118.58:085.31:360.63:394.78:014:18First Quarter19Thu
20Fri9:458.59:324.92:191.54:333.78:014:19First Quarter20Fri
21Sat10:198.411:174.93:072.65:252.58:024:19First Quarter21Sat
22Sun10:558.44:023.96:151.38:024:20First Quarter22Sun
23Mon1:215.411:34 AM8.45:095.07:030.08:034:20Waxing Gibbous23Mon
24Tue2:496.312:158.46:245.97:49-1.18:034:21Waxing Gibbous24Tue
25Wed3:497.11:008.47:366.58:34-1.98:034:22Waxing Gibbous25Wed
26Thu4:377.91:498.38:406.79:19-2.58:044:22Full Moon26Thu
27Fri5:208.42:418.29:386.710:04-2.68:044:23Full Moon27Fri
28Sat6:008.73:357.910:356.610:48-2.48:044:24Full Moon28Sat
29Sun6:398.84:307.611:336.211:33-1.88:044:25Waning Gibbous29Sun
30Mon7:188.95:267.012:335.88:044:26Waning Gibbous30Mon
31Tue7:558.86:256.412:17-1.01:375.28:044:27Waning 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 10:03 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 spring phase. Tonight's moon is 15% 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 Waxing Crescent (15% 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