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

TIDE TIMES for Saturday, August 1, 2026
The tide is currently rising in Roche Harbor, San Juan Island, WA.
Next low tide (tomorrow) : 2:14 am (4.1 ft)
Next high tide : in 5h 32m at 8:25 pm (7.8 ft)
Sunset today : 8:50 pm
Sunrise tomorrow : 5:47 am
Moon phase : Waning Gibbous (90% illuminated)
Tide Station Location : Station #9449834
Common Questions About Tides

Roche Harbor, San Juan Island, WA Tides - Aug 1973

DateHigh TideLow TideSunMoonDate
AMftPMftAMftPMftRiseSet
1Wed6:406.68:128.01:114.01:06-0.25:478:50Waxing Crescent1Wed
2Thu7:456.08:417.92:073.11:491.15:488:49Waxing Crescent2Thu
3Fri8:575.69:097.83:022.32:342.45:498:47Waxing Crescent3Fri
4Sat10:255.39:397.53:571.63:213.75:518:46First Quarter4Sat
5Sun12:205.34:511.14:164.95:528:44First Quarter5Sun
6Mon2:095.85:470.75:295.95:538:43First Quarter6Mon
7Tue3:276.46:450.57:036.45:558:41First Quarter7Tue
8Wed4:206.97:410.28:376.55:568:39Waxing Gibbous8Wed
9Thu12:186.55:007.18:330.09:406.45:578:38Waxing Gibbous9Thu
10Fri1:156.55:327.39:18-0.210:186.25:598:36Waxing Gibbous10Fri
11Sat2:136.55:597.39:57-0.310:465.96:008:34Waxing Gibbous11Sat
12Sun3:086.66:217.310:33-0.411:145.56:028:33Full Moon12Sun
13Mon4:006.66:397.411:06-0.311:455.06:038:31Full Moon13Mon
14Tue4:496.66:557.411:38-0.16:048:29Full Moon14Tue
15Wed5:396.57:137.512:184.312:110.46:068:27Full Moon15Wed
16Thu6:316.37:357.612:543.612:441.06:078:25Waning Gibbous16Thu
17Fri7:276.18:007.61:332.71:191.96:098:24Waning Gibbous17Fri
18Sat8:275.98:277.52:161.81:562.96:108:22Waning Gibbous18Sat
19Sun9:375.78:577.53:031.02:364.06:118:20Third Quarter19Sun
20Mon11:065.69:297.43:540.33:215.06:138:18Third Quarter20Mon
21Tue1:045.84:51-0.24:215.96:148:16Third Quarter21Tue
22Wed2:416.35:53-0.75:486.56:168:14Third Quarter22Wed
23Thu3:396.86:59-1.07:236.66:178:12Waning Crescent23Thu
24Fri12:077.14:207.28:02-1.38:396.36:188:10Waning Crescent24Fri
25Sat1:227.04:557.48:59-1.49:365.66:208:08Waning Crescent25Sat
26Sun2:387.05:267.69:49-1.210:254.86:218:07New Moon26Sun
27Mon3:497.05:557.710:36-0.811:113.86:238:05New Moon27Mon
28Tue4:556.96:217.711:19-0.111:552.96:248:03New Moon28Tue
29Wed5:576.86:477.712:010.86:258:01New Moon29Wed
30Thu6:576.67:127.612:402.012:431.96:277:59Waxing Crescent30Thu
31Fri7:586.47:387.41:251.31:273.06:287:57Waxing Crescent31Fri
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 11:19 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 90% 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 (90% 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