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 38m 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 - Apr 1976

DateHigh TideLow TideSunMoonDate
AMftPMftAMftPMftRiseSet
1Thu5:127.16:416.811:420.85:496:43Waxing Crescent1Thu
2Fri5:397.07:256.812:004.412:170.45:476:45Waxing Crescent2Fri
3Sat6:096.98:136.812:404.912:540.35:456:46Waxing Crescent3Sat
4Sun6:416.79:076.71:245.41:350.25:426:47Waxing Crescent4Sun
5Mon7:156.510:116.72:155.82:210.35:406:49Waxing Crescent5Mon
6Tue7:546.211:196.73:176.03:130.45:386:50First Quarter6Tue
7Wed8:476.04:346.04:110.65:366:52First Quarter7Wed
8Thu12:196.89:59 AM5.75:515.75:130.85:346:53First Quarter8Thu
9Fri1:056.911:22 AM5.76:495.16:151.05:326:55Waxing Gibbous9Fri
10Sat1:417.112:465.87:334.27:131.35:306:56Waxing Gibbous10Sat
11Sun2:147.32:066.18:143.08:061.75:286:58Waxing Gibbous11Sun
12Mon2:457.53:186.68:541.78:562.25:266:59Waxing Gibbous12Mon
13Tue3:177.74:227.09:350.49:442.95:247:01Full Moon13Tue
14Wed3:507.85:217.410:17-0.710:323.65:227:02Full Moon14Wed
15Thu4:267.96:197.611:02-1.511:224.35:207:04Full Moon15Thu
16Fri5:047.87:177.711:48-1.95:187:05Waning Gibbous16Fri
17Sat5:447.68:187.712:164.912:37-1.95:167:07Waning Gibbous17Sat
18Sun6:287.29:217.61:175.41:28-1.55:157:08Waning Gibbous18Sun
19Mon7:166.710:277.52:285.62:22-0.85:137:10Third Quarter19Mon
20Tue8:136.111:317.53:545.63:200.05:117:11Third Quarter20Tue
21Wed9:225.55:365.24:220.85:097:13Third Quarter21Wed
22Thu12:277.410:52 AM5.16:594.55:281.75:077:14Third Quarter22Thu
23Fri1:147.412:425.07:513.86:322.45:057:15Waning Crescent23Fri
24Sat1:537.32:125.38:273.07:313.05:037:17Waning Crescent24Sat
25Sun3:237.14:175.89:532.39:203.56:028:18Waning Crescent25Sun
26Mon3:457.05:106.210:171.510:044.06:008:20Waning Crescent26Mon
27Tue4:037.05:546.610:420.910:444.55:588:21New Moon27Tue
28Wed4:226.96:346.911:090.311:234.95:568:23New Moon28Wed
29Thu4:476.97:117.111:38-0.25:558:24New Moon29Thu
30Fri5:156.97:487.312:025.312:09-0.65:538:26New Moon30Fri
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