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

TIDE TIMES for Tuesday, August 4, 2026
The tide is currently rising in Roche Harbor, San Juan Island, WA.
Next low tide (tomorrow) : 4:34 am (1.0 ft)
Next high tide : in 6h 22m at 9:37 pm (7.7 ft)
Sunset today : 8:45 pm
Sunrise tomorrow : 5:51 am
Moon phase : Third Quarter (64% illuminated)
Tide Station Location : Station #9449834
Common Questions About Tides

Roche Harbor, San Juan Island, WA Tides - Jun 2094

DateHigh TideLow TideSunMoonDate
AMftPMftAMftPMftRiseSet
1Tue5:337.29:178.11:016.71:07-2.85:149:07Waning Gibbous1Tue
2Wed6:166.910:088.22:046.71:55-2.65:139:08Waning Gibbous2Wed
3Thu7:096.510:588.23:186.62:47-2.05:129:09Waning Gibbous3Thu
4Fri8:195.811:458.14:446.03:41-1.25:129:10Third Quarter4Fri
5Sat9:445.26:125.24:38-0.15:119:10Third Quarter5Sat
6Sun12:288.111:25 AM4.77:184.05:371.25:119:11Third Quarter6Sun
7Mon1:078.11:254.68:072.76:392.45:119:12Waning Crescent7Mon
8Tue1:428.03:145.18:461.47:433.65:109:13Waning Crescent8Tue
9Wed2:147.94:325.99:230.28:444.65:109:13Waning Crescent9Wed
10Thu2:447.85:336.79:57-0.89:425.45:109:14Waning Crescent10Thu
11Fri3:147.66:247.310:31-1.510:376.05:109:15New Moon11Fri
12Sat3:437.47:107.811:06-2.011:316.45:099:15New Moon12Sat
13Sun4:147.27:538.011:41-2.15:099:16New Moon13Sun
14Mon4:486.98:358.112:276.612:19-2.05:099:16New Moon14Mon
15Tue5:256.69:158.11:276.712:58-1.75:099:17Waxing Crescent15Tue
16Wed6:056.39:538.02:346.51:39-1.35:099:17Waxing Crescent16Wed
17Thu6:515.910:307.93:496.22:21-0.75:099:17Waxing Crescent17Thu
18Fri7:435.411:037.75:085.83:050.05:099:18Waxing Crescent18Fri
19Sat8:464.911:337.66:125.23:490.95:109:18First Quarter19Sat
20Sun10:024.56:574.54:341.85:109:18First Quarter20Sun
21Mon12:017.611:33 AM4.27:293.65:232.75:109:19First Quarter21Mon
22Tue12:287.51:354.37:562.76:183.75:109:19First Quarter22Tue
23Wed12:567.53:314.98:231.67:194.65:119:19Waxing Gibbous23Wed
24Thu1:257.54:385.78:520.58:195.45:119:19Waxing Gibbous24Thu
25Fri1:557.55:276.59:24-0.69:156.05:119:19Waxing Gibbous25Fri
26Sat2:277.56:107.110:00-1.610:066.45:129:19Full Moon26Sat
27Sun3:027.66:507.610:38-2.410:566.75:129:19Full Moon27Sun
28Mon3:427.67:318.011:20-3.011:486.85:139:19Full Moon28Mon
29Tue4:287.58:128.212:04-3.25:149:18Full Moon29Tue
30Wed5:217.38:548.312:436.712:51-3.15:149:18Waning Gibbous30Wed
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 1:05 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 transitional phase. Tonight's moon is 64% 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 shifting between spring and neap.

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 Third Quarter (64% illuminated). This places Roche Harbor, San Juan Island, WA in a transitional tide cycle, so tidal ranges are shifting between spring and neap 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