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

TIDE TIMES for Friday, July 31, 2026
The tide is currently rising in Roche Harbor, San Juan Island, WA.
Next low tide : 12:35 pm (-0.7 ft)
Next high tide : in 1h 30m at 5:34 am (6.5 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 - May 1976

DateHigh TideLow TideSunMoonDate
AMftPMftAMftPMftRiseSet
1Sat5:476.88:267.412:435.612:43-0.85:518:27Waxing Crescent1Sat
2Sun6:206.69:087.41:285.81:21-0.85:498:29Waxing Crescent2Sun
3Mon6:556.49:537.42:186.02:02-0.85:488:30Waxing Crescent3Mon
4Tue7:326.110:417.43:156.02:46-0.55:468:31Waxing Crescent4Tue
5Wed8:195.811:287.44:215.93:35-0.25:458:33First Quarter5Wed
6Thu9:255.45:325.54:280.45:438:34First Quarter6Thu
7Fri12:137.410:49 AM5.16:354.85:261.05:428:36First Quarter7Fri
8Sat12:547.412:215.07:263.86:281.85:408:37First Quarter8Sat
9Sun1:317.51:595.28:102.67:312.55:398:38Waxing Gibbous9Sun
10Mon2:077.63:285.88:511.28:303.35:378:40Waxing Gibbous10Mon
11Tue2:437.74:406.59:32-0.29:264.05:368:41Waxing Gibbous11Tue
12Wed3:207.85:407.110:14-1.310:204.65:348:43Full Moon12Wed
13Thu3:587.96:357.610:56-2.211:135.25:338:44Full Moon13Thu
14Fri4:397.87:268.011:40-2.75:328:45Full Moon14Fri
15Sat5:227.68:178.112:085.512:26-2.75:308:47Waning Gibbous15Sat
16Sun6:077.29:098.11:075.81:12-2.45:298:48Waning Gibbous16Sun
17Mon6:566.810:008.12:145.82:01-1.75:288:49Waning Gibbous17Mon
18Tue7:496.210:517.93:315.62:51-0.85:278:50Waning Gibbous18Tue
19Wed8:505.511:407.84:585.13:430.25:258:52Third Quarter19Wed
20Thu10:034.96:234.54:371.35:248:53Third Quarter20Thu
21Fri12:257.611:41 AM4.57:283.75:352.35:238:54Third Quarter21Fri
22Sat1:047.51:484.68:142.86:373.35:228:55Third Quarter22Sat
23Sun1:367.33:215.18:492.07:404.25:218:57Waning Crescent23Sun
24Mon2:017.14:275.79:181.38:394.85:208:58Waning Crescent24Mon
25Tue2:257.15:186.39:440.69:315.35:198:59Waning Crescent25Tue
26Wed2:507.06:006.710:11-0.110:175.75:189:00Waning Crescent26Wed
27Thu3:197.06:377.110:39-0.611:006.05:179:01New Moon27Thu
28Fri3:527.07:117.411:10-1.111:416.25:179:02New Moon28Fri
29Sat4:266.97:437.611:42-1.45:169:03New Moon29Sat
30Sun5:036.88:177.712:246.312:18-1.55:159:04New Moon30Sun
31Mon5:426.68:527.81:106.312:56-1.55:149:05Waxing Crescent31Mon
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 9:04 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 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