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

TIDE TIMES for Thursday, July 30, 2026
The tide is currently rising in Roche Harbor, San Juan Island, WA.
Next low tide : 12:01 pm (-1.0 ft)
Next high tide : in 1h 19m at 4:44 am (6.7 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 - Oct 1978

DateHigh TideLow TideSunMoonDate
AMftPMftAMftPMftRiseSet
1Sun4:586.55:127.210:502.311:171.97:126:52New Moon1Sun
2Mon5:436.75:377.211:262.711:481.27:136:50New Moon2Mon
3Tue6:296.96:067.312:033.27:146:48New Moon3Tue
4Wed7:187.06:377.212:240.512:433.87:166:46Waxing Crescent4Wed
5Thu8:107.17:117.11:030.01:274.47:176:44Waxing Crescent5Thu
6Fri9:077.17:486.91:47-0.42:175.07:196:42Waxing Crescent6Fri
7Sat10:127.08:306.72:36-0.53:175.57:206:40First Quarter7Sat
8Sun11:247.09:236.43:30-0.44:305.77:226:38First Quarter8Sun
9Mon12:377.14:30-0.25:565.67:236:36First Quarter9Mon
10Tue1:397.35:350.27:185.17:256:33First Quarter10Tue
11Wed2:297.46:430.68:194.37:266:31Waxing Gibbous11Wed
12Thu1:215.83:117.67:481.09:063.37:286:29Waxing Gibbous12Thu
13Fri2:466.13:477.78:471.59:472.37:296:28Waxing Gibbous13Fri
14Sat4:006.54:197.79:392.010:261.47:316:26Full Moon14Sat
15Sun5:026.94:497.710:262.611:040.57:326:24Full Moon15Sun
16Mon5:587.25:187.611:133.311:42-0.17:346:22Full Moon16Mon
17Tue6:517.45:487.411:594.07:356:20Full Moon17Tue
18Wed7:427.56:197.112:20-0.412:484.77:376:18Waning Gibbous18Wed
19Thu8:337.66:516.81:00-0.51:415.27:386:16Waning Gibbous19Thu
20Fri9:277.57:276.51:42-0.42:435.67:406:14Waning Gibbous20Fri
21Sat10:257.48:076.12:260.03:575.87:416:12Waning Gibbous21Sat
22Sun11:267.48:565.63:140.45:335.87:436:10Third Quarter22Sun
23Mon12:267.34:061.07:145.47:446:08Third Quarter23Mon
24Tue1:177.35:041.68:124.97:466:07Third Quarter24Tue
25Wed1:587.36:062.18:464.47:486:05Third Quarter25Wed
26Thu12:455.02:297.27:082.59:093.77:496:03Waning Crescent26Thu
27Fri2:135.22:537.38:042.99:293.07:516:01Waning Crescent27Fri
28Sat3:235.63:167.38:523.29:522.27:526:00Waning Crescent28Sat
29Sun3:186.12:417.48:353.69:171.36:544:58Waning Crescent29Sun
30Mon4:076.63:097.59:164.09:460.46:554:56New Moon30Mon
31Tue4:527.13:397.59:564.410:19-0.46:574:55New Moon31Tue
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 8:22 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