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

TIDE TIMES for Friday, July 31, 2026
The tide is currently falling in Roche Harbor, San Juan Island, WA.
Next low tide : in 1h 24m at 12:35 pm (-0.7 ft)
Next high tide : 8:05 pm (7.7 ft)
Sunset today : 8:51 pm
Sunrise tomorrow : 5:46 am
Moon phase : Waning Gibbous (95% illuminated)
Tide Station Location : Station #9449834
Common Questions About Tides

Roche Harbor, San Juan Island, WA Tides - Mar 2086

DateHigh TideLow TideSunMoonDate
AMftPMftAMftPMftRiseSet
1Fri5:377.65:266.511:283.211:242.36:525:57Full Moon1Fri
2Sat5:537.66:116.412:012.66:505:58Waning Gibbous2Sat
3Sun6:147.56:596.312:352.06:486:00Waning Gibbous3Sun
4Mon6:407.57:526.212:323.71:131.56:466:01Waning Gibbous4Mon
5Tue7:087.48:546.11:084.51:541.16:446:03Waning Gibbous5Tue
6Wed7:387.210:146.01:465.22:390.86:426:04Third Quarter6Wed
7Thu8:097.02:305.93:310.66:406:06Third Quarter7Thu
8Fri12:076.28:46 AM6.93:326.44:300.46:386:07Third Quarter8Fri
9Sat1:316.59:39 AM6.75:046.75:340.26:366:09Third Quarter9Sat
10Sun3:186.811:51 AM6.77:316.67:360.07:347:11Waning Crescent10Sun
11Mon3:517.11:096.78:326.08:33-0.27:327:12Waning Crescent11Mon
12Tue4:197.32:276.89:205.29:23-0.17:307:14Waning Crescent12Tue
13Wed4:447.63:407.010:044.110:100.27:277:15New Moon13Wed
14Thu5:107.84:487.210:472.810:550.87:257:17New Moon14Thu
15Fri5:387.95:527.311:311.611:391.77:237:18New Moon15Fri
16Sat6:078.16:557.312:170.57:217:20New Moon16Sat
17Sun6:398.17:587.212:252.71:04-0.37:197:21Waxing Crescent17Sun
18Mon7:138.09:047.11:123.71:53-0.77:177:23Waxing Crescent18Mon
19Tue7:497.810:197.02:034.62:45-0.87:157:24Waxing Crescent19Tue
20Wed8:297.411:426.93:025.43:40-0.67:137:26First Quarter20Wed
21Thu9:146.94:156.04:39-0.17:117:27First Quarter21Thu
22Fri1:047.010:09 AM6.45:516.25:450.47:097:29First Quarter22Fri
23Sat2:127.111:20 AM5.97:535.96:540.97:077:30First Quarter23Sat
24Sun3:057.212:485.79:085.47:591.27:057:32Waxing Gibbous24Sun
25Mon3:467.32:205.79:484.88:541.67:027:33Waxing Gibbous25Mon
26Tue4:187.33:335.910:154.19:392.07:007:35Waxing Gibbous26Tue
27Wed4:437.24:306.110:363.410:172.46:587:36Waxing Gibbous27Wed
28Thu5:007.15:176.310:592.710:522.86:567:38Full Moon28Thu
29Fri5:147.16:016.511:232.011:273.46:547:39Full Moon29Fri
30Sat5:297.16:426.711:511.36:527:41Full Moon30Sat
31Sun5:517.17:246.812:013.912:210.76:507:42Full Moon31Sun
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 4:20 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 95% 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 Waning Gibbous (95% 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