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 : 4:34 pm (4.5 ft)
Next high tide : in 2h 56m at 12:47 pm (4.9 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 - Nov 2071

DateHigh TideLow TideSunMoonDate
AMftPMftAMftPMftRiseSet
1Sun12:477.45:022.47:414.16:594:52First Quarter1Sun
2Mon1:167.46:042.98:043.47:014:51Waxing Gibbous2Mon
3Tue1:285.21:407.47:003.38:262.67:024:49Waxing Gibbous3Tue
4Wed2:385.72:057.47:493.78:501.77:044:47Waxing Gibbous4Wed
5Thu3:316.22:317.58:334.19:160.87:054:46Waxing Gibbous5Thu
6Fri4:186.73:007.59:154.59:47-0.17:074:44Full Moon6Fri
7Sat5:027.23:327.69:564.910:21-0.97:094:43Full Moon7Sat
8Sun5:477.64:067.510:395.410:58-1.57:104:42Full Moon8Sun
9Mon6:337.94:427.411:255.711:40-1.87:124:40Waning Gibbous9Mon
10Tue7:228.15:217.212:186.07:134:39Waning Gibbous10Tue
11Wed8:138.26:076.912:26-1.71:196.17:154:37Waning Gibbous11Wed
12Thu9:088.27:026.41:15-1.42:326.07:164:36Waning Gibbous12Thu
13Fri10:028.28:125.82:07-0.83:575.67:184:35Third Quarter13Fri
14Sat10:568.19:385.33:040.05:254.97:194:34Third Quarter14Sat
15Sun11:458.111:215.14:061.06:343.87:214:32Third Quarter15Sun
16Mon12:298.15:122.17:222.77:224:31Waning Crescent16Mon
17Tue1:115.41:088.16:183.08:021.67:244:30Waning Crescent17Tue
18Wed2:376.01:448.07:213.98:380.67:264:29Waning Crescent18Wed
19Thu3:436.72:167.98:194.69:12-0.27:274:28Waning Crescent19Thu
20Fri4:387.32:487.89:125.29:46-0.87:284:27New Moon20Fri
21Sat5:267.83:197.610:025.710:21-1.17:304:26New Moon21Sat
22Sun6:118.13:517.410:526.010:56-1.27:314:25New Moon22Sun
23Mon6:548.34:267.111:446.311:33-1.17:334:24Waxing Crescent23Mon
24Tue7:358.35:036.812:416.47:344:23Waxing Crescent24Tue
25Wed8:178.35:436.412:11-0.81:466.37:364:23Waxing Crescent25Wed
26Thu8:578.26:286.012:52-0.32:596.17:374:22Waxing Crescent26Thu
27Fri9:378.17:225.51:340.44:195.77:384:21First Quarter27Fri
28Sat10:148.08:285.12:181.15:305.17:404:21First Quarter28Sat
29Sun10:497.99:474.73:041.96:194.57:414:20First Quarter29Sun
30Mon11:227.811:244.63:562.76:523.77:424:19First Quarter30Mon
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 2:40 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 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