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

TIDE TIMES for Thursday, July 9, 2026
The tide is currently falling in Roche Harbor, San Juan Island, WA.
Next low tide : in 30m at 5:57 pm (5.8 ft)
Next high tide (tomorrow) : 12:02 am (7.9 ft)
Sunset today : 9:15 pm
Sunrise tomorrow : 5:20 am
Moon phase : Waning Crescent (28% illuminated)
Tide Station Location : Station #9449834
Common Questions About Tides

Roche Harbor, San Juan Island, WA Tides - May 1999

DateHigh TideLow TideSunMoonDate
AMftPMftAMftPMftRiseSet
1Sat5:257.07:397.112:090.05:528:26Full Moon1Sat
2Sun5:516.88:207.212:375.012:41-0.35:508:28Waning Gibbous2Sun
3Mon6:206.79:037.31:235.51:16-0.55:498:29Waning Gibbous3Mon
4Tue6:526.49:507.32:155.81:54-0.55:478:31Waning Gibbous4Tue
5Wed7:256.110:417.33:166.02:35-0.35:468:32Waning Gibbous5Wed
6Thu8:005.811:347.34:296.13:20-0.15:448:33Third Quarter6Thu
7Fri8:455.55:595.94:100.35:428:35Third Quarter7Fri
8Sat12:257.39:55 AM5.27:245.55:060.75:418:36Third Quarter8Sat
9Sun1:097.311:20 AM4.97:534.96:061.15:398:38Third Quarter9Sun
10Mon1:477.412:485.08:194.17:081.65:388:39Waning Crescent10Mon
11Tue2:207.52:165.28:483.08:062.15:378:40Waning Crescent11Tue
12Wed2:517.63:365.89:211.89:002.75:358:42Waning Crescent12Wed
13Thu3:237.74:456.49:580.49:513.45:348:43Waning Crescent13Thu
14Fri3:567.85:477.010:37-0.910:414.15:328:45New Moon14Fri
15Sat4:307.86:447.511:18-1.911:324.85:318:46New Moon15Sat
16Sun5:077.87:397.912:02-2.55:308:47New Moon16Sun
17Mon5:477.68:358.112:265.412:49-2.85:288:48Waxing Crescent17Mon
18Tue6:307.39:338.11:275.81:38-2.65:278:50Waxing Crescent18Tue
19Wed7:186.810:318.12:376.02:29-2.05:268:51Waxing Crescent19Wed
20Thu8:126.111:298.04:035.93:23-1.25:258:52First Quarter20Thu
21Fri9:185.55:495.44:20-0.25:248:54First Quarter21Fri
22Sat12:248.010:42 AM4.97:244.65:200.95:238:55First Quarter22Sat
23Sun1:127.812:324.68:213.76:231.95:228:56First Quarter23Sun
24Mon1:547.72:264.89:022.87:262.85:218:57Waxing Gibbous24Mon
25Tue2:297.53:485.39:322.08:253.75:208:58Waxing Gibbous25Tue
26Wed2:567.44:505.99:561.29:184.35:198:59Waxing Gibbous26Wed
27Thu3:187.25:416.410:190.510:064.95:189:01Waxing Gibbous27Thu
28Fri3:387.16:256.910:44-0.110:515.45:179:02Full Moon28Fri
29Sat4:027.07:047.211:11-0.611:355.85:169:03Full Moon29Sat
30Sun4:296.97:417.411:40-0.95:159:04Full Moon30Sun
31Mon5:006.88:177.612:206.112:13-1.25:159:05Full 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 8:59 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 transitional phase. Tonight's moon is 28% 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 shifting between spring and neap.

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 (28% illuminated). This places Roche Harbor, San Juan Island, WA in a transitional tide cycle, so tidal ranges are shifting between spring and neap 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