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

TIDE TIMES for Sunday, July 19, 2026
The tide is currently rising in Roche Harbor, San Juan Island, WA.
Next low tide (tomorrow) : 4:51 am (2.5 ft)
Next high tide : in 5h 56m at 9:59 pm (7.9 ft)
Sunset today : 9:06 pm
Sunrise tomorrow : 5:31 am
Moon phase : First Quarter (33% illuminated)
Tide Station Location : Station #9449834
Common Questions About Tides

Roche Harbor, San Juan Island, WA Tides - Jul 2071

DateHigh TideLow TideSunMoonDate
AMftPMftAMftPMftRiseSet
1Wed7:246.49:388.32:244.92:08-1.35:149:18Waxing Crescent1Wed
2Thu8:325.710:198.33:354.22:58-0.15:159:18First Quarter2Thu
3Fri9:505.111:008.14:473.43:501.25:169:17First Quarter3Fri
4Sat11:324.711:407.95:572.54:452.65:169:17First Quarter4Sat
5Sun1:324.97:001.65:483.95:179:17First Quarter5Sun
6Mon12:207.73:075.57:540.86:584.95:189:16Waxing Gibbous6Mon
7Tue12:597.54:166.28:390.28:115.65:199:16Waxing Gibbous7Tue
8Wed1:377.25:096.89:18-0.39:175.95:209:15Waxing Gibbous8Wed
9Thu2:167.15:527.29:52-0.610:136.15:219:14Waxing Gibbous9Thu
10Fri2:556.96:297.510:26-0.811:006.15:229:14Full Moon10Fri
11Sat3:356.87:027.610:59-0.911:426.05:239:13Full Moon11Sat
12Sun4:176.77:317.611:33-0.95:239:12Full Moon12Sun
13Mon5:006.67:577.712:225.812:07-0.85:249:12Full Moon13Mon
14Tue5:446.48:227.71:055.612:42-0.55:269:11Waning Gibbous14Tue
15Wed6:306.18:467.71:495.31:18-0.15:279:10Waning Gibbous15Wed
16Thu7:185.89:137.72:354.81:540.45:289:09Waning Gibbous16Thu
17Fri8:115.49:437.73:224.32:311.15:299:08Waning Gibbous17Fri
18Sat9:125.010:157.64:103.73:092.05:309:07Third Quarter18Sat
19Sun10:244.710:487.64:592.93:512.95:319:06Third Quarter19Sun
20Mon11:544.711:247.55:492.14:403.95:329:05Third Quarter20Mon
21Tue1:525.06:391.15:444.85:339:04Third Quarter21Tue
22Wed12:037.53:255.77:300.16:595.55:359:03Waning Crescent22Wed
23Thu12:467.54:236.48:19-0.88:115.85:369:02Waning Crescent23Thu
24Fri1:357.65:087.09:07-1.69:145.95:379:01Waning Crescent24Fri
25Sat2:297.65:487.49:55-2.210:105.75:388:59New Moon25Sat
26Sun3:267.66:257.810:41-2.511:045.35:398:58New Moon26Sun
27Mon4:257.67:028.011:28-2.411:584.95:418:57New Moon27Mon
28Tue5:257.37:398.112:14-1.95:428:55Waxing Crescent28Tue
29Wed6:266.98:158.112:554.31:01-1.15:438:54Waxing Crescent29Wed
30Thu7:286.48:528.11:543.61:48-0.15:458:53Waxing Crescent30Thu
31Fri8:355.99:298.02:552.92:371.15:468:51Waxing Crescent31Fri
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 1:25 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 transitional phase. Tonight's moon is 33% 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 First Quarter (33% 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