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 4h 27m at 12:35 pm (-0.7 ft)
Next high tide : 8:05 pm (7.7 ft)
Sunset today : 8:51 pm
Sunrise tomorrow : 5:46 am
Moon phase : Waning Gibbous (95% illuminated)
Tide Station Location : Station #9449834
Common Questions About Tides

Roche Harbor, San Juan Island, WA Tides - Dec 2085

DateHigh TideLow TideSunMoonDate
AMftPMftAMftPMftRiseSet
1Sat5:598.52:577.810:217.110:30-2.37:444:19Full Moon1Sat
2Sun6:418.73:397.511:177.111:10-2.17:464:18Full Moon2Sun
3Mon7:228.74:227.112:167.07:474:18Waning Gibbous3Mon
4Tue8:028.65:096.71:216.87:484:17Waning Gibbous4Tue
5Wed8:408.55:596.212:33-0.92:346.47:494:17Waning Gibbous5Wed
6Thu9:158.36:565.61:15-0.13:485.87:504:17Waning Gibbous6Thu
7Fri9:478.28:045.11:580.94:535.17:514:17Third Quarter7Fri
8Sat10:148.09:304.62:411.95:424.27:524:17Third Quarter8Sat
9Sun10:397.911:434.53:253.16:203.37:534:16Third Quarter9Sun
10Mon11:047.84:154.26:522.47:544:16Third Quarter10Mon
11Tue2:095.111:32 AM7.85:165.37:221.47:554:16Waning Crescent11Tue
12Wed3:246.012:027.76:266.17:520.57:564:16Waning Crescent12Wed
13Thu4:116.712:337.77:336.88:23-0.47:574:17Waning Crescent13Thu
14Fri4:487.41:077.88:297.28:57-1.27:584:17Waning Crescent14Fri
15Sat5:227.91:447.89:187.49:33-1.87:584:17New Moon15Sat
16Sun5:558.22:267.810:037.510:12-2.37:594:17New Moon16Sun
17Mon6:288.53:137.810:487.410:53-2.48:004:17New Moon17Mon
18Tue7:028.74:067.611:397.211:36-2.38:004:18Waxing Crescent18Tue
19Wed7:368.75:047.212:366.78:014:18Waxing Crescent19Wed
20Thu8:118.86:096.612:21-1.71:406.08:014:19Waxing Crescent20Thu
21Fri8:468.87:225.91:06-0.82:475.18:024:19Waxing Crescent21Fri
22Sat9:208.88:475.21:520.43:543.98:024:20First Quarter22Sat
23Sun9:548.710:384.92:391.94:572.68:034:20First Quarter23Sun
24Mon10:298.63:303.55:541.38:034:21First Quarter24Mon
25Tue12:565.311:04 AM8.54:305.06:460.28:034:22Waxing Gibbous25Tue
26Wed2:376.211:41 AM8.35:476.27:33-0.88:044:22Waxing Gibbous26Wed
27Thu3:437.212:218.17:107.08:16-1.48:044:23Waxing Gibbous27Thu
28Fri4:327.91:047.98:267.48:57-1.78:044:24Waxing Gibbous28Fri
29Sat5:138.41:507.79:307.49:37-1.88:044:25Full Moon29Sat
30Sun5:508.62:397.510:247.310:15-1.78:044:26Full Moon30Sun
31Mon6:258.73:277.311:127.110:53-1.28:044:27Full Moon31Mon
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 4:20 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 95% 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 Gibbous (95% 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