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 : 12:01 pm (-1.0 ft)
Next high tide : in 14m at 4:44 am (6.7 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 1978

DateHigh TideLow TideSunMoonDate
AMftPMftAMftPMftRiseSet
1Tue2:336.66:007.310:03-0.310:425.85:468:50Waning Crescent1Tue
2Wed3:206.66:297.410:37-0.411:175.65:488:49New Moon2Wed
3Thu4:056.66:547.411:11-0.411:515.35:498:48New Moon3Thu
4Fri4:496.67:167.411:45-0.35:508:46New Moon4Fri
5Sat5:336.57:377.512:265.012:19-0.15:528:44New Moon5Sat
6Sun6:196.38:007.51:034.612:530.35:538:43Waxing Crescent6Sun
7Mon7:076.08:277.51:434.11:290.95:548:41Waxing Crescent7Mon
8Tue7:595.88:577.52:263.52:061.65:568:40Waxing Crescent8Tue
9Wed8:585.59:297.53:122.92:452.45:578:38Waxing Crescent9Wed
10Thu10:075.210:047.44:002.23:283.35:588:36First Quarter10Thu
11Fri11:335.110:427.34:531.54:194.36:008:35First Quarter11Fri
12Sat1:255.45:500.85:255.16:018:33First Quarter12Sat
13Sun2:565.96:480.06:445.66:038:31Waxing Gibbous13Sun
14Mon12:157.23:556.57:46-0.67:595.86:048:29Waxing Gibbous14Mon
15Tue1:137.34:397.08:41-1.29:025.66:058:28Waxing Gibbous15Tue
16Wed2:157.35:187.49:32-1.69:575.16:078:26Waxing Gibbous16Wed
17Thu3:187.45:547.610:20-1.710:484.56:088:24Full Moon17Thu
18Fri4:207.46:287.811:06-1.411:383.86:108:22Full Moon18Fri
19Sat5:217.27:027.911:52-0.96:118:20Full Moon19Sat
20Sun6:217.07:357.912:293.212:370.06:128:18Waning Gibbous20Sun
21Mon7:216.78:097.81:212.51:241.06:148:17Waning Gibbous21Mon
22Tue8:256.38:447.62:152.02:122.16:158:15Waning Gibbous22Tue
23Wed9:365.99:207.33:101.53:033.26:178:13Third Quarter23Wed
24Thu11:045.79:587.04:061.34:014.26:188:11Third Quarter24Thu
25Fri12:465.85:051.15:115.06:198:09Third Quarter25Fri
26Sat2:136.16:061.06:375.56:218:07Third Quarter26Sat
27Sun3:186.57:070.98:055.76:228:05Waning Crescent27Sun
28Mon12:266.24:076.88:040.89:115.56:248:03Waning Crescent28Mon
29Tue1:266.14:457.08:530.79:545.36:258:01Waning Crescent29Tue
30Wed2:256.25:167.19:350.610:245.06:267:59Waning Crescent30Wed
31Thu3:186.35:407.110:120.610:524.66:287:57New Moon31Thu
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 8:22 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 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