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

TIDE TIMES for Thursday, July 30, 2026
The tide is currently falling in Roche Harbor, San Juan Island, WA.
Next low tide (tomorrow) : in 3h 58m at 12:53 am (5.6 ft)
Next high tide (tomorrow) : 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 - Dec 1976

DateHigh TideLow TideSunMoonDate
AMftPMftAMftPMftRiseSet
1Wed2:115.512:367.76:144.88:041.47:444:19Waxing Gibbous1Wed
2Thu3:196.21:027.57:205.68:320.77:454:18Waxing Gibbous2Thu
3Fri4:116.91:297.48:186.18:590.17:464:18Waxing Gibbous3Fri
4Sat4:547.41:587.49:096.49:27-0.47:474:18Full Moon4Sat
5Sun5:307.72:307.39:546.79:57-0.77:494:17Full Moon5Sun
6Mon6:038.03:067.210:366.810:28-1.07:504:17Full Moon6Mon
7Tue6:348.13:437.111:186.811:02-1.07:514:17Full Moon7Tue
8Wed7:048.34:216.912:036.87:524:17Waning Gibbous8Wed
9Thu7:358.35:036.712:526.67:534:17Waning Gibbous9Thu
10Fri8:078.45:496.312:15-0.81:466.47:544:17Waning Gibbous10Fri
11Sat8:408.46:445.912:55-0.42:435.97:554:16Waning Gibbous11Sat
12Sun9:158.47:545.41:370.33:415.27:564:17Third Quarter12Sun
13Mon9:508.49:184.92:211.14:364.27:574:17Third Quarter13Mon
14Tue10:258.410:584.83:092.25:283.07:574:17Third Quarter14Tue
15Wed11:028.44:053.46:161.87:584:17Third Quarter15Wed
16Thu12:595.211:39 AM8.45:104.57:020.47:594:17Waning Crescent16Thu
17Fri2:356.112:198.46:225.57:47-0.88:004:17Waning Crescent17Fri
18Sat3:397.01:018.47:326.18:31-1.78:004:18Waning Crescent18Sat
19Sun4:307.71:478.48:356.59:15-2.48:014:18New Moon19Sun
20Mon5:168.32:368.39:336.79:59-2.78:014:19New Moon20Mon
21Tue5:588.73:288.110:306.610:44-2.68:024:19New Moon21Tue
22Wed6:408.84:217.711:276.411:28-2.18:024:20Waxing Crescent22Wed
23Thu7:208.95:167.212:296.08:034:20Waxing Crescent23Thu
24Fri7:598.86:136.612:13-1.31:355.68:034:21Waxing Crescent24Fri
25Sat8:378.77:145.912:58-0.32:444.98:044:21Waxing Crescent25Sat
26Sun9:148.58:255.31:430.93:514.28:044:22First Quarter26Sun
27Mon9:488.310:014.82:292.14:553.48:044:23First Quarter27Mon
28Tue10:208.13:173.45:512.68:044:24First Quarter28Tue
29Wed12:255.010:51 AM7.94:134.76:391.98:044:25First Quarter29Wed
30Thu2:125.611:22 AM7.75:225.77:201.28:044:25Waxing Gibbous30Thu
31Fri3:216.411:57 AM7.56:416.48:000.78:054:26Waxing Gibbous31Fri
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