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

TIDE TIMES for Monday, August 3, 2026
The tide is currently rising in Roche Harbor, San Juan Island, WA.
Next low tide : 2:18 pm (1.9 ft)
Next high tide : in 1h 17m at 8:27 am (5.4 ft)
Sunset today : 8:47 pm
Sunrise tomorrow : 5:50 am
Moon phase : Waning Gibbous (74% illuminated)
Tide Station Location : Station #9449834
Common Questions About Tides

Roche Harbor, San Juan Island, WA Tides - Oct 1970

DateHigh TideLow TideSunMoonDate
AMftPMftAMftPMftRiseSet
1Thu6:246.65:437.111:493.77:116:52New Moon1Thu
2Fri7:126.86:047.112:120.712:234.57:136:50Waxing Crescent2Fri
3Sat8:026.96:277.012:440.01:015.27:146:48Waxing Crescent3Sat
4Sun8:577.06:476.91:20-0.51:425.97:166:46Waxing Crescent4Sun
5Mon10:037.06:596.82:02-0.82:316.57:176:44Waxing Crescent5Mon
6Tue11:237.06:546.72:49-0.93:377.07:196:42First Quarter6Tue
7Wed12:487.23:44-0.85:187.17:206:40First Quarter7Wed
8Thu1:507.34:48-0.57:226:38First Quarter8Thu
9Fri2:337.55:57-0.38:186.17:236:36First Quarter9Fri
10Sat3:057.67:050.18:485.17:256:34Waxing Gibbous10Sat
11Sun1:155.93:327.68:070.59:223.87:266:32Waxing Gibbous11Sun
12Mon2:466.13:577.79:011.29:592.37:286:30Waxing Gibbous12Mon
13Tue4:076.54:207.89:492.010:370.87:296:28Full Moon13Tue
14Wed5:176.94:447.910:353.111:15-0.57:316:26Full Moon14Wed
15Thu6:217.45:107.811:214.211:55-1.47:326:24Full Moon15Thu
16Fri7:217.75:377.712:105.27:346:22Waning Gibbous16Fri
17Sat8:217.96:057.412:36-1.91:036.07:356:20Waning Gibbous17Sat
18Sun9:237.96:357.11:19-2.02:056.67:376:18Waning Gibbous18Sun
19Mon10:297.97:076.62:05-1.63:286.97:386:16Waning Gibbous19Mon
20Tue11:387.87:406.12:55-1.06:306.77:406:14Third Quarter20Tue
21Wed12:437.73:50-0.27:416:12Third Quarter21Wed
22Thu1:377.74:520.68:455.67:436:10Third Quarter22Thu
23Fri2:207.65:591.39:114.97:446:09Third Quarter23Fri
24Sat12:074.92:517.57:041.99:304.27:466:07Waning Crescent24Sat
25Sun1:565.12:137.47:012.58:463.46:475:05Waning Crescent25Sun
26Mon2:205.42:267.37:493.19:012.56:495:03Waning Crescent26Mon
27Tue3:235.92:377.38:303.79:201.56:515:01Waning Crescent27Tue
28Wed4:156.42:517.39:094.49:430.56:525:00New Moon28Wed
29Thu5:016.83:117.39:465.110:09-0.36:544:58New Moon29Thu
30Fri5:457.33:327.310:245.810:38-1.16:554:56New Moon30Fri
31Sat6:297.63:547.311:046.311:12-1.66:574:55New Moon31Sat
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 11:22 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 74% 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 Gibbous (74% 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