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

TIDE TIMES for Saturday, August 1, 2026
The tide is currently rising in Roche Harbor, San Juan Island, WA.
Next low tide (tomorrow) : 2:14 am (4.1 ft)
Next high tide : in 6h 36m at 8:25 pm (7.8 ft)
Sunset today : 8:50 pm
Sunrise tomorrow : 5:47 am
Moon phase : Waning Gibbous (90% illuminated)
Tide Station Location : Station #9449834
Common Questions About Tides

Roche Harbor, San Juan Island, WA Tides - Sep 1973

DateHigh TideLow TideSunMoonDate
AMftPMftAMftPMftRiseSet
1Sat9:046.28:067.22:100.82:134.16:307:54Waxing Crescent1Sat
2Sun10:226.18:366.92:570.63:075.06:317:52First Quarter2Sun
3Mon11:566.29:106.63:470.54:135.76:327:50First Quarter3Mon
4Tue1:296.44:410.65:416.26:347:48First Quarter4Tue
5Wed2:406.75:420.77:306.36:357:46First Quarter5Wed
6Thu3:316.96:480.88:506.06:377:44Waxing Gibbous6Thu
7Fri4:097.07:500.89:295.76:387:42Waxing Gibbous7Fri
8Sat1:045.94:387.18:420.89:555.36:397:40Waxing Gibbous8Sat
9Sun2:116.04:597.19:250.810:174.76:417:38Waxing Gibbous9Sun
10Mon3:116.25:157.110:010.810:424.16:427:36Full Moon10Mon
11Tue4:066.45:297.210:351.111:093.26:447:34Full Moon11Tue
12Wed4:596.55:467.311:091.511:402.36:457:32Full Moon12Wed
13Thu5:516.66:087.311:432.16:467:30Full Moon13Thu
14Fri6:446.76:337.412:141.412:192.96:487:27Waning Gibbous14Fri
15Sat7:406.77:007.412:530.512:583.86:497:25Waning Gibbous15Sat
16Sun8:406.77:307.31:35-0.21:404.76:517:23Waning Gibbous16Sun
17Mon9:506.68:027.22:23-0.72:285.56:527:21Waning Gibbous17Mon
18Tue11:146.68:407.03:16-0.93:286.16:537:19Third Quarter18Tue
19Wed12:456.74:15-0.94:506.56:557:17Third Quarter19Wed
20Thu1:587.05:21-0.76:316.46:567:15Third Quarter20Thu
21Fri2:507.26:31-0.48:005.86:587:13Waning Crescent21Fri
22Sat12:176.23:307.47:38-0.18:575.06:597:10Waning Crescent22Sat
23Sun1:476.24:047.58:370.39:403.97:007:08Waning Crescent23Sun
24Mon3:106.34:327.59:280.810:192.87:027:06Waning Crescent24Mon
25Tue4:226.54:587.510:141.510:551.87:037:04New Moon25Tue
26Wed5:246.85:217.510:572.311:320.97:057:02New Moon26Wed
27Thu6:227.05:447.411:403.27:067:00New Moon27Thu
28Fri7:167.16:087.312:090.212:234.17:086:58Waxing Crescent28Fri
29Sat8:117.16:347.112:46-0.31:104.97:096:56Waxing Crescent29Sat
30Sun9:077.17:036.81:26-0.42:035.57:106:54Waxing Crescent30Sun
DateHigh TideLow TideSunMoonDate
AMftPMftAMftPMftRiseSet
Tidal Data Source: (9449834)

Common Questions About Roche Harbor, San Juan Island, WA Tides

Show All
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 11:19 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 90% 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 Waning Gibbous (90% 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