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

TIDE TIMES for Friday, July 10, 2026
The tide is currently falling in Roche Harbor, San Juan Island, WA.
Next low tide : in 2h 52m at 7:56 am (-1.3 ft)
Next high tide : 4:38 pm (6.5 ft)
Sunset today : 9:14 pm
Sunrise tomorrow : 5:21 am
Moon phase : Waning Crescent (18% illuminated)
Tide Station Location : Station #9449834
Common Questions About Tides

Roche Harbor, San Juan Island, WA Tides - Oct 1998

DateHigh TideLow TideSunMoonDate
AMftPMftAMftPMftRiseSet
1Thu12:225.83:167.17:270.98:504.97:126:52Waxing Gibbous1Thu
2Fri1:346.03:477.38:230.89:234.17:136:50Waxing Gibbous2Fri
3Sat2:436.34:157.49:130.89:593.17:156:47Waxing Gibbous3Sat
4Sun3:486.74:457.610:001.010:362.07:166:45Full Moon4Sun
5Mon4:507.05:157.710:451.511:171.07:186:43Full Moon5Mon
6Tue5:507.35:487.811:302.17:196:41Full Moon6Tue
7Wed6:497.56:227.712:010.012:173.07:216:39Waning Gibbous7Wed
8Thu7:497.56:597.612:47-0.71:083.87:226:37Waning Gibbous8Thu
9Fri8:547.57:397.31:36-1.02:044.77:236:35Waning Gibbous9Fri
10Sat10:047.48:246.92:28-1.13:105.37:256:33Third Quarter10Sat
11Sun11:207.49:166.43:23-0.74:335.67:266:31Third Quarter11Sun
12Mon12:347.54:23-0.26:205.67:286:29Third Quarter12Mon
13Tue1:397.55:290.48:045.17:296:27Third Quarter13Tue
14Wed2:337.66:371.09:014.47:316:25Waning Crescent14Wed
15Thu1:215.43:167.67:431.59:393.87:326:23Waning Crescent15Thu
16Fri2:485.63:527.58:412.010:063.17:346:21Waning Crescent16Fri
17Sat3:556.04:207.49:292.510:292.57:356:19Waning Crescent17Sat
18Sun4:496.34:417.310:112.910:521.97:376:17New Moon18Sun
19Mon5:356.64:587.210:503.411:181.37:396:16New Moon19Mon
20Tue6:176.95:167.111:284.011:460.87:406:14New Moon20Tue
21Wed6:577.05:407.012:074.57:426:12New Moon21Wed
22Thu7:367.26:076.912:160.412:485.07:436:10Waxing Crescent22Thu
23Fri8:187.36:386.712:490.11:335.47:456:08Waxing Crescent23Fri
24Sat9:037.37:106.41:250.02:245.87:466:06Waxing Crescent24Sat
25Sun8:537.36:446.21:040.02:266.06:485:05Waxing Crescent25Sun
26Mon9:497.37:225.91:470.23:426.16:495:03First Quarter26Mon
27Tue10:487.48:195.62:360.45:136.06:515:01First Quarter27Tue
28Wed11:437.49:385.33:310.76:235.56:524:59First Quarter28Wed
29Thu12:297.54:331.16:574.96:544:58First Quarter29Thu
30Fri1:077.65:381.57:283.96:564:56Waxing Gibbous30Fri
31Sat12:305.51:417.76:391.98:022.86:574:54Waxing Gibbous31Sat
DateHigh TideLow TideSunMoonDate
AMftPMftAMftPMftRiseSet
Tidal Data Source: (9449834)

Common Questions About Roche Harbor, San Juan Island, WA Tides

Show All
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 12:17 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 18% 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 Crescent (18% 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