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

TIDE TIMES for Wednesday, July 29, 2026
The tide is currently rising in Roche Harbor, San Juan Island, WA.
Next low tide (tomorrow) : 12:17 am (6.1 ft)
Next high tide : in 1h 22m at 7:27 pm (7.7 ft)
Sunset today : 8:54 pm
Sunrise tomorrow : 5:43 am
Moon phase : Full Moon (100% illuminated)
Tide Station Location : Station #9449834
Common Questions About Tides

Roche Harbor, San Juan Island, WA Tides - Nov 1979

DateHigh TideLow TideSunMoonDate
AMftPMftAMftPMftRiseSet
1Thu1:596.02:177.97:352.38:401.46:584:53Waxing Gibbous1Thu
2Fri3:136.52:508.08:293.09:190.27:004:52Full Moon2Fri
3Sat4:167.13:238.09:203.69:59-0.77:014:50Full Moon3Sat
4Sun5:137.63:577.910:104.310:39-1.37:034:49Full Moon4Sun
5Mon6:067.94:317.611:015.011:20-1.57:044:47Full Moon5Mon
6Tue6:598.15:077.311:565.57:064:46Waning Gibbous6Tue
7Wed7:528.25:466.912:03-1.512:575.97:084:44Waning Gibbous7Wed
8Thu8:478.16:276.412:47-1.12:116.17:094:43Waning Gibbous8Thu
9Fri9:438.07:155.91:34-0.53:466.07:114:41Third Quarter9Fri
10Sat10:397.98:145.32:240.35:395.57:124:40Third Quarter10Sat
11Sun11:317.89:314.93:181.16:464.97:144:38Third Quarter11Sun
12Mon12:157.74:161.97:294.37:154:37Third Quarter12Mon
13Tue12:517.65:192.77:583.67:174:36Waning Crescent13Tue
14Wed1:064.91:187.56:213.38:192.87:194:35Waning Crescent14Wed
15Thu2:275.41:407.57:173.98:402.17:204:33Waning Crescent15Thu
16Fri3:245.92:037.58:064.49:021.37:224:32Waning Crescent16Fri
17Sat4:106.52:297.58:504.89:270.57:234:31Waning Crescent17Sat
18Sun4:516.92:577.59:315.29:55-0.27:254:30New Moon18Sun
19Mon5:297.43:287.510:115.610:26-0.87:264:29New Moon19Mon
20Tue6:087.74:017.410:536.011:01-1.27:284:28New Moon20Tue
21Wed6:488.04:357.211:386.211:39-1.57:294:27Waxing Crescent21Wed
22Thu7:328.25:127.012:296.47:314:26Waxing Crescent22Thu
23Fri8:188.35:546.712:22-1.51:306.47:324:25Waxing Crescent23Fri
24Sat9:078.36:476.31:08-1.22:406.27:334:24Waxing Crescent24Sat
25Sun9:568.37:585.71:58-0.63:595.77:354:23First Quarter25Sun
26Mon10:448.39:245.32:520.15:154.97:364:23First Quarter26Mon
27Tue11:298.311:045.03:501.16:163.87:384:22First Quarter27Tue
28Wed12:108.34:542.27:042.67:394:21Waxing Gibbous28Wed
29Thu12:565.312:498.36:003.27:461.37:404:20Waxing Gibbous29Thu
30Fri2:295.91:268.27:054.18:260.27:424:20Waxing Gibbous30Fri
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 9:52 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 100% 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 (100% 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