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 2h 31m 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 - May 1989

DateHigh TideLow TideSunMoonDate
AMftPMftAMftPMftRiseSet
1Mon2:227.52:025.38:423.37:581.95:518:27Waning Crescent1Mon
2Tue2:487.63:375.89:181.78:532.95:508:28Waning Crescent2Tue
3Wed3:137.84:546.59:550.09:444.05:488:30Waning Crescent3Wed
4Thu3:407.95:597.210:34-1.410:354.95:468:31New Moon4Thu
5Fri4:097.96:587.711:15-2.511:275.85:458:33New Moon5Fri
6Sat4:417.87:548.111:57-3.15:438:34New Moon6Sat
7Sun5:167.68:508.212:226.412:42-3.15:428:35Waxing Crescent7Sun
8Mon5:547.39:468.11:236.81:29-2.75:408:37Waxing Crescent8Mon
9Tue6:366.810:448.02:376.82:19-2.05:398:38Waxing Crescent9Tue
10Wed7:256.311:417.94:176.63:11-1.15:378:40First Quarter10Wed
11Thu8:265.66:326.14:07-0.15:368:41First Quarter11Thu
12Fri12:327.79:46 AM5.07:425.35:050.95:348:42First Quarter12Fri
13Sat1:147.611:30 AM4.58:254.46:041.95:338:44First Quarter13Sat
14Sun1:487.41:454.58:563.57:042.95:328:45Waxing Gibbous14Sun
15Mon2:127.33:275.09:182.58:013.85:308:46Waxing Gibbous15Mon
16Tue2:277.14:375.69:381.58:534.65:298:48Waxing Gibbous16Tue
17Wed2:407.15:316.29:580.69:425.45:288:49Waxing Gibbous17Wed
18Thu2:577.16:166.810:21-0.210:276.05:278:50Full Moon18Thu
19Fri3:197.06:567.310:47-0.911:116.45:268:52Full Moon19Fri
20Sat3:437.07:347.611:16-1.511:556.85:248:53Full Moon20Sat
21Sun4:097.08:137.811:49-1.95:238:54Full Moon21Sun
22Mon4:346.98:537.912:417.012:26-2.15:228:55Waning Gibbous22Mon
23Tue4:516.89:357.91:317.11:07-2.15:218:56Waning Gibbous23Tue
24Wed4:586.610:197.92:307.11:52-1.95:208:58Waning Gibbous24Wed
25Thu5:246.411:007.93:426.92:39-1.55:198:59Waning Gibbous25Thu
26Fri6:275.911:387.95:036.43:28-0.95:189:00Third Quarter26Fri
27Sat9:045.26:085.64:200.05:179:01Third Quarter27Sat
28Sun12:107.910:51 AM4.76:534.45:141.25:179:02Third Quarter28Sun
29Mon12:407.912:454.67:332.96:122.55:169:03Third Quarter29Mon
30Tue1:087.92:475.18:131.27:143.85:159:04Waning Crescent30Tue
31Wed1:368.04:186.08:52-0.48:175.15:149:05Waning Crescent31Wed
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