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 1h 03m 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 - Nov 2084

DateHigh TideLow TideSunMoonDate
AMftPMftAMftPMftRiseSet
1Wed8:578.15:597.412:50-2.51:306.98:005:51Waxing Crescent1Wed
2Thu9:548.16:427.11:38-2.32:377.08:025:49Waxing Crescent2Thu
3Fri10:528.17:436.52:31-1.84:026.88:045:48First Quarter3Fri
4Sat11:468.19:085.93:27-1.15:486.28:055:46First Quarter4Sat
5Sun11:348.09:485.33:26-0.16:165.17:074:45First Quarter5Sun
6Mon12:158.04:291.17:053.87:084:43First Quarter6Mon
7Tue12:508.05:342.27:432.57:104:42Waxing Gibbous7Tue
8Wed1:395.41:218.06:383.48:171.27:114:40Waxing Gibbous8Wed
9Thu3:046.11:487.97:384.48:500.07:134:39Waxing Gibbous9Thu
10Fri4:096.92:137.88:345.39:22-0.97:154:38Full Moon10Fri
11Sat5:037.52:387.79:266.09:54-1.57:164:36Full Moon11Sat
12Sun5:518.03:057.510:176.510:28-1.77:184:35Full Moon12Sun
13Mon6:358.33:347.311:096.911:03-1.77:194:34Full Moon13Mon
14Tue7:198.44:057.012:047.07:214:33Waning Gibbous14Tue
15Wed8:018.34:396.71:077.07:224:31Waning Gibbous15Wed
16Thu8:448.25:186.412:21-1.12:276.97:244:30Waning Gibbous16Thu
17Fri9:278.16:036.01:03-0.54:306.57:254:29Waning Gibbous17Fri
18Sat10:078.07:055.51:480.25:466.07:274:28Third Quarter18Sat
19Sun10:417.98:265.02:340.96:265.37:284:27Third Quarter19Sun
20Mon11:107.89:594.63:221.86:494.57:304:26Third Quarter20Mon
21Tue11:357.811:504.64:132.77:063.67:314:25Third Quarter21Tue
22Wed11:597.75:093.77:252.57:334:24Waning Crescent22Wed
23Thu1:535.112:257.86:084.67:491.37:344:24Waning Crescent23Thu
24Fri3:115.912:527.87:075.48:170.17:354:23Waning Crescent24Fri
25Sat4:066.71:207.98:026.18:49-1.17:374:22Waning Crescent25Sat
26Sun4:527.51:518.08:536.79:25-2.17:384:21New Moon26Sun
27Mon5:358.02:258.19:427.110:05-2.77:394:21New Moon27Mon
28Tue6:188.43:038.110:317.310:48-3.17:414:20New Moon28Tue
29Wed7:018.73:497.911:237.411:34-3.07:424:19Waxing Crescent29Wed
30Thu7:468.74:437.612:247.37:434:19Waxing Crescent30Thu
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