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 14m 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 - Apr 2088

DateHigh TideLow TideSunMoonDate
AMftPMftAMftPMftRiseSet
1Thu3:007.41:465.88:514.58:151.16:477:44Waxing Gibbous1Thu
2Fri3:407.53:126.09:373.69:101.56:457:46Waxing Gibbous2Fri
3Sat4:147.54:216.310:132.89:582.16:437:47Waxing Gibbous3Sat
4Sun4:437.55:196.610:471.910:422.76:417:49Full Moon4Sun
5Mon5:087.46:096.811:191.211:243.36:397:50Full Moon5Mon
6Tue5:317.36:577.011:520.66:377:52Full Moon6Tue
7Wed5:557.27:427.112:063.912:260.26:357:53Full Moon7Wed
8Thu6:227.18:287.112:494.41:020.06:337:55Waning Gibbous8Thu
9Fri6:526.99:167.01:364.91:410.06:317:56Waning Gibbous9Fri
10Sat7:256.610:096.92:275.42:220.16:297:58Waning Gibbous10Sat
11Sun8:026.311:086.83:255.73:060.46:277:59Waning Gibbous11Sun
12Mon8:446.04:345.83:540.76:258:01Third Quarter12Mon
13Tue12:116.89:35 AM5.75:555.74:481.16:238:02Third Quarter13Tue
14Wed1:076.810:40 AM5.47:155.45:471.56:218:04Third Quarter14Wed
15Thu1:516.911:56 AM5.28:074.96:481.86:198:05Third Quarter15Thu
16Fri2:246.91:165.38:404.37:452.16:178:06Waning Crescent16Fri
17Sat2:517.02:355.59:073.48:362.46:158:08Waning Crescent17Sat
18Sun3:177.13:456.09:372.49:232.76:138:09Waning Crescent18Sun
19Mon3:457.34:466.510:091.210:083.26:118:11New Moon19Mon
20Tue4:157.45:427.010:450.110:523.76:098:12New Moon20Tue
21Wed4:487.56:357.411:24-0.911:384.36:078:14New Moon21Wed
22Thu5:237.67:297.612:06-1.76:068:15New Moon22Thu
23Fri6:017.68:247.712:264.812:51-2.16:048:17Waxing Crescent23Fri
24Sat6:427.49:227.71:195.31:40-2.16:028:18Waxing Crescent24Sat
25Sun7:287.010:237.72:215.62:32-1.86:008:20Waxing Crescent25Sun
26Mon8:226.511:257.63:335.73:28-1.15:588:21First Quarter26Mon
27Tue9:266.05:005.54:27-0.35:578:23First Quarter27Tue
28Wed12:257.610:47 AM5.46:374.95:300.65:558:24First Quarter28Wed
29Thu1:187.612:275.17:564.06:361.65:538:26First Quarter29Thu
30Fri2:047.62:165.28:483.07:412.45:518:27Waxing 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 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