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

TIDE TIMES for Friday, July 31, 2026
The tide is currently falling in Roche Harbor, San Juan Island, WA.
Next low tide : in 1h 10m at 12:53 am (5.6 ft)
Next high tide : 5:34 am (6.5 ft)
Sunset today : 8:53 pm
Sunrise tomorrow : 5:44 am
Moon phase : Full Moon (99% illuminated)
Tide Station Location : Station #9449834
Common Questions About Tides

Roche Harbor, San Juan Island, WA Tides - Sep 1976

DateHigh TideLow TideSunMoonDate
AMftPMftAMftPMftRiseSet
1Wed1:006.34:58-0.25:175.56:307:54First Quarter1Wed
2Thu2:196.66:05-0.26:485.76:317:52First Quarter2Thu
3Fri3:187.07:13-0.18:145.56:337:50Waxing Gibbous3Fri
4Sat12:566.44:047.28:150.09:175.06:347:48Waxing Gibbous4Sat
5Sun2:116.44:437.49:090.210:024.56:367:46Waxing Gibbous5Sun
6Mon3:206.45:167.49:550.410:393.96:377:44Full Moon6Mon
7Tue4:206.55:437.310:360.811:133.36:387:42Full Moon7Tue
8Wed5:116.66:067.311:131.311:472.76:407:39Full Moon8Wed
9Thu5:596.66:267.211:501.96:417:37Full Moon9Thu
10Fri6:446.66:477.112:212.112:282.66:437:35Waning Gibbous10Fri
11Sat7:306.57:107.012:571.71:073.36:447:33Waning Gibbous11Sat
12Sun8:176.47:386.81:341.31:484.06:457:31Waning Gibbous12Sun
13Mon9:106.38:096.72:151.12:334.66:477:29Waning Gibbous13Mon
14Tue10:126.28:456.52:581.03:255.26:487:27Third Quarter14Tue
15Wed11:316.19:256.23:461.04:295.76:507:25Third Quarter15Wed
16Thu1:036.24:391.05:515.96:517:23Third Quarter16Thu
17Fri2:106.45:391.17:145.96:527:20Third Quarter17Fri
18Sat2:556.66:411.08:115.66:547:18Waning Crescent18Sat
19Sun12:245.93:276.87:390.98:495.06:557:16Waning Crescent19Sun
20Mon1:346.03:537.08:320.89:234.36:577:14Waning Crescent20Mon
21Tue2:436.34:187.29:180.89:573.36:587:12Waning Crescent21Tue
22Wed3:476.64:457.410:021.010:342.26:597:10New Moon22Wed
23Thu4:486.95:137.610:451.511:141.17:017:08New Moon23Thu
24Fri5:477.25:457.711:292.111:570.17:027:06New Moon24Fri
25Sat6:457.36:197.712:142.97:047:04Waxing Crescent25Sat
26Sun7:457.46:557.712:43-0.61:023.77:057:01Waxing Crescent26Sun
27Mon8:497.37:357.51:32-1.01:554.57:076:59Waxing Crescent27Mon
28Tue9:597.28:207.12:24-1.12:575.27:086:57First Quarter28Tue
29Wed11:167.19:126.73:20-0.94:125.67:096:55First Quarter29Wed
30Thu12:337.24:22-0.45:455.67:116:53First Quarter30Thu
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 3:13 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 spring phase. Tonight's moon is 99% 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 Full Moon (99% 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