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

TIDE TIMES for Thursday, July 23, 2026
The tide is currently falling in Roche Harbor, San Juan Island, WA.
Next low tide : in 2h 21m at 7:27 am (0.2 ft)
Next high tide : 4:07 pm (6.4 ft)
Sunset today : 9:02 pm
Sunrise tomorrow : 5:35 am
Moon phase : Waxing Gibbous (72% illuminated)
Tide Station Location : Station #9449834
Common Questions About Tides

Roche Harbor, San Juan Island, WA Tides - Sep 2074

DateHigh TideLow TideSunMoonDate
AMftPMftAMftPMftRiseSet
1Sat12:276.84:067.27:59-0.78:495.86:307:53Waxing Gibbous1Sat
2Sun1:346.74:507.58:55-0.89:455.46:327:51Waxing Gibbous2Sun
3Mon2:426.75:277.69:46-0.810:304.86:337:49Full Moon3Mon
4Tue3:456.86:007.710:31-0.511:114.36:357:47Full Moon4Tue
5Wed4:436.86:307.611:13-0.111:503.76:367:45Full Moon5Wed
6Thu5:366.76:567.511:530.56:377:43Full Moon6Thu
7Fri6:266.67:207.312:303.112:331.36:397:41Waning Gibbous7Fri
8Sat7:176.47:437.21:102.61:142.16:407:39Waning Gibbous8Sat
9Sun8:106.38:087.01:512.11:573.06:427:37Waning Gibbous9Sun
10Mon9:086.18:366.82:341.72:433.96:437:35Waning Gibbous10Mon
11Tue10:185.99:076.53:191.53:374.86:447:33Third Quarter11Tue
12Wed11:536.09:446.24:081.34:445.46:467:31Third Quarter12Wed
13Thu1:346.25:011.26:135.96:477:28Third Quarter13Thu
14Fri2:446.55:591.27:515.96:497:26Third Quarter14Fri
15Sat3:326.86:591.08:555.86:507:24Waning Crescent15Sat
16Sun12:265.84:067.07:560.89:275.56:517:22Waning Crescent16Sun
17Mon1:316.04:347.18:460.69:515.16:537:20Waning Crescent17Mon
18Tue2:336.24:577.29:300.410:164.56:547:18Waning Crescent18Tue
19Wed3:316.55:197.310:110.310:463.86:567:16New Moon19Wed
20Thu4:276.75:437.410:510.511:212.96:577:14New Moon20Thu
21Fri5:226.96:107.511:310.911:592.06:587:11New Moon21Fri
22Sat6:187.06:397.612:131.67:007:09Waxing Crescent22Sat
23Sun7:167.07:117.612:421.112:572.57:017:07Waxing Crescent23Sun
24Mon8:197.07:457.51:280.31:453.57:037:05Waxing Crescent24Mon
25Tue9:286.98:237.22:18-0.32:384.57:047:03Waxing Crescent25Tue
26Wed10:496.89:057.03:13-0.63:435.37:067:01First Quarter26Wed
27Thu12:186.94:11-0.65:055.87:076:59First Quarter27Thu
28Fri1:387.25:16-0.46:445.97:086:57First Quarter28Fri
29Sat2:407.46:24-0.18:185.57:106:55Waxing Gibbous29Sat
30Sun12:226.03:297.67:320.29:164.97:116:53Waxing Gibbous30Sun
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 11:47 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 72% 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 Waxing Gibbous (72% 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