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

TIDE TIMES for Tuesday, July 21, 2026
The tide is currently rising in Roche Harbor, San Juan Island, WA.
Next low tide (tomorrow) : 6:38 am (0.8 ft)
Next high tide : in 3h 34m at 10:51 pm (7.5 ft)
Sunset today : 9:04 pm
Sunrise tomorrow : 5:33 am
Moon phase : First Quarter (53% illuminated)
Tide Station Location : Station #9449834
Common Questions About Tides

Roche Harbor, San Juan Island, WA Tides - Jun 1989

DateHigh TideLow TideSunMoonDate
AMftPMftAMftPMftRiseSet
1Thu2:068.05:246.99:32-1.79:196.05:149:06Waning Crescent1Thu
2Fri2:378.06:197.610:12-2.810:186.75:139:07New Moon2Fri
3Sat3:127.97:088.110:54-3.311:167.05:139:08New Moon3Sat
4Sun3:517.77:558.311:37-3.45:129:09New Moon4Sun
5Mon4:357.48:418.412:167.112:22-3.25:119:10Waxing Crescent5Mon
6Tue5:247.09:268.31:217.01:08-2.65:119:11Waxing Crescent6Tue
7Wed6:166.510:098.22:376.71:55-1.85:119:11Waxing Crescent7Wed
8Thu7:135.910:508.04:086.22:42-0.85:109:12Waxing Crescent8Thu
9Fri8:175.311:257.85:335.53:290.35:109:13First Quarter9Fri
10Sat9:354.611:547.66:344.64:161.45:109:14First Quarter10Sat
11Sun11:204.27:183.65:042.75:099:14First Quarter11Sun
12Mon12:157.51:594.37:522.65:584.05:099:15First Quarter12Mon
13Tue12:347.33:475.18:211.67:005.15:099:15Waxing Gibbous13Tue
14Wed12:557.34:545.98:480.68:076.05:099:16Waxing Gibbous14Wed
15Thu1:187.25:426.79:16-0.29:116.65:099:16Waxing Gibbous15Thu
16Fri1:457.16:207.29:45-0.910:067.05:099:17Waxing Gibbous16Fri
17Sat2:137.16:547.610:17-1.510:547.25:099:17Full Moon17Sat
18Sun2:457.17:277.810:51-2.011:377.35:099:17Full Moon18Sun
19Mon3:197.18:008.011:28-2.35:099:18Full Moon19Mon
20Tue4:007.18:328.112:197.312:08-2.55:099:18Full Moon20Tue
21Wed4:496.99:058.11:077.212:51-2.45:109:18Waning Gibbous21Wed
22Thu5:476.69:378.22:026.81:34-2.15:109:18Waning Gibbous22Thu
23Fri6:536.210:088.23:046.22:18-1.45:109:19Waning Gibbous23Fri
24Sat8:085.510:388.24:065.33:02-0.35:109:19Third Quarter24Sat
25Sun9:354.911:078.25:054.13:471.05:119:19Third Quarter25Sun
26Mon11:184.511:368.16:002.64:342.65:119:19Third Quarter26Mon
27Tue1:334.76:511.15:294.25:129:19Third Quarter27Tue
28Wed12:058.13:305.67:39-0.36:375.65:129:19Waning Crescent28Wed
29Thu12:378.04:446.68:26-1.57:556.65:139:18Waning Crescent29Thu
30Fri1:127.95:377.49:11-2.39:097.15:139:18Waning Crescent30Fri
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 2:44 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 neap phase. Tonight's moon is 53% 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 minimum.

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 First Quarter (53% illuminated). This places Roche Harbor, San Juan Island, WA in a neap tide cycle, so tidal ranges are near their weekly minimum 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