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

TIDE TIMES for Thursday, July 30, 2026
The tide is currently falling in Roche Harbor, San Juan Island, WA.
Next low tide : in 1h 55m at 12:01 pm (-1.0 ft)
Next high tide : 7:46 pm (7.7 ft)
Sunset today : 8:53 pm
Sunrise tomorrow : 5:44 am
Moon phase : Full Moon (99% illuminated)
Tide Station Location : Station #9449834
Common Questions About Tides

Roche Harbor, San Juan Island, WA Tides - Nov 1977

DateHigh TideLow TideSunMoonDate
AMftPMftAMftPMftRiseSet
1Tue9:217.66:585.91:210.23:246.06:594:53Waning Gibbous1Tue
2Wed10:097.57:515.52:060.65:005.87:004:51Third Quarter2Wed
3Thu10:567.59:015.12:551.16:205.37:024:49Third Quarter3Thu
4Fri11:387.510:224.93:501.76:544.77:044:48Third Quarter4Fri
5Sat12:147.54:492.27:154.07:054:46Third Quarter5Sat
6Sun12:467.55:502.87:393.07:074:45Waning Crescent6Sun
7Mon1:205.31:187.66:483.38:061.97:084:43Waning Crescent7Mon
8Tue2:355.91:507.77:413.88:380.77:104:42Waning Crescent8Tue
9Wed3:366.62:237.98:314.39:13-0.47:124:41New Moon9Wed
10Thu4:307.22:588.09:194.89:51-1.47:134:39New Moon10Thu
11Fri5:217.83:368.010:075.210:32-2.17:154:38New Moon11Fri
12Sat6:118.14:167.910:575.611:17-2.57:164:36New Moon12Sat
13Sun7:028.45:017.711:525.97:184:35Waxing Crescent13Sun
14Mon7:548.55:507.312:04-2.412:556.17:194:34Waxing Crescent14Mon
15Tue8:498.46:466.712:54-1.92:096.07:214:33Waxing Crescent15Tue
16Wed9:438.47:526.01:46-1.13:365.57:224:32First Quarter16Wed
17Thu10:378.39:135.42:42-0.15:104.87:244:30First Quarter17Thu
18Fri11:278.210:585.03:411.16:263.87:254:29First Quarter18Fri
19Sat12:128.14:452.37:182.87:274:28Waxing Gibbous19Sat
20Sun12:565.212:528.05:523.47:581.97:284:27Waxing Gibbous20Sun
21Mon2:255.81:267.86:584.38:301.07:304:26Waxing Gibbous21Mon
22Tue3:316.41:557.77:585.08:590.37:314:25Waxing Gibbous22Tue
23Wed4:257.12:217.58:515.59:28-0.27:334:25Full Moon23Wed
24Thu5:107.52:477.49:406.09:57-0.67:344:24Full Moon24Thu
25Fri5:507.83:167.210:256.310:28-0.87:364:23Full Moon25Fri
26Sat6:278.03:487.111:116.411:00-0.97:374:22Full Moon26Sat
27Sun7:028.14:236.911:586.511:35-0.87:384:21Waning Gibbous27Sun
28Mon7:368.25:006.612:516.57:404:21Waning Gibbous28Mon
29Tue8:108.25:416.312:12-0.51:506.47:414:20Waning Gibbous29Tue
30Wed8:448.26:265.912:50-0.12:576.17:424:20Waning Gibbous30Wed
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 3:53 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 99% 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 Full Moon (99% 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