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

TIDE TIMES for Thursday, July 16, 2026
The tide is currently falling in Roche Harbor, San Juan Island, WA.
Next low tide (tomorrow) : in 4h 53m at 1:44 am (5.4 ft)
Next high tide (tomorrow) : 6:35 am (6.6 ft)
Sunset today : 9:09 pm
Sunrise tomorrow : 5:27 am
Moon phase : Waxing Crescent (8% illuminated)
Tide Station Location : Station #9449834
Common Questions About Tides

Roche Harbor, San Juan Island, WA Tides - Nov 1990

DateHigh TideLow TideSunMoonDate
AMftPMftAMftPMftRiseSet
1Thu3:496.72:317.88:434.49:26-1.06:594:53Full Moon1Thu
2Fri4:487.42:598.09:305.210:04-2.17:004:51Full Moon2Fri
3Sat5:447.93:308.010:176.010:46-2.97:024:50Full Moon3Sat
4Sun6:398.34:048.011:076.611:31-3.27:034:48Waning Gibbous4Sun
5Mon7:358.44:437.812:037.07:054:47Waning Gibbous5Mon
6Tue8:338.45:287.412:20-3.01:117.27:074:45Waning Gibbous6Tue
7Wed9:328.36:256.81:13-2.32:387.07:084:44Third Quarter7Wed
8Thu10:308.27:396.02:08-1.44:476.47:104:42Third Quarter8Thu
9Fri11:228.29:135.33:07-0.36:255.47:114:41Third Quarter9Fri
10Sat12:068.14:090.97:154.27:134:39Third Quarter10Sat
11Sun12:448.05:142.17:513.07:144:38Waning Crescent11Sun
12Mon1:165.11:147.96:173.38:201.97:164:37Waning Crescent12Mon
13Tue2:465.81:377.77:184.38:450.97:174:35Waning Crescent13Tue
14Wed3:526.51:567.68:145.29:090.17:194:34Waning Crescent14Wed
15Thu4:467.22:137.49:056.09:35-0.67:214:33New Moon15Thu
16Fri5:327.72:347.39:546.510:02-1.17:224:32New Moon16Fri
17Sat6:148.02:587.210:426.910:32-1.37:244:31New Moon17Sat
18Sun6:538.23:247.111:317.111:05-1.37:254:30New Moon18Sun
19Mon7:318.33:536.912:247.27:274:29Waxing Crescent19Mon
20Tue8:098.24:206.71:277.27:284:27Waxing Crescent20Tue
21Wed8:498.23:376.412:20-0.93:047.17:304:27Waxing Crescent21Wed
22Thu9:288.11:01-0.57:314:26Waxing Crescent22Thu
23Fri10:058.11:440.07:324:25First Quarter23Fri
24Sat10:388.08:195.12:290.66:365.57:344:24First Quarter24Sat
25Sun11:078.010:024.73:161.46:284.57:354:23First Quarter25Sun
26Mon11:348.011:514.74:082.46:463.37:374:22First Quarter26Mon
27Tue12:008.05:053.57:131.97:384:22Waxing Gibbous27Tue
28Wed1:475.312:278.16:084.67:450.37:394:21Waxing Gibbous28Wed
29Thu3:136.312:558.27:115.68:22-1.17:414:20Waxing Gibbous29Thu
30Fri4:147.21:268.38:106.49:01-2.47:424:20Full Moon30Fri
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 4:09 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 8% 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 Waxing Crescent (8% 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