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 4h 27m 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 - Jul 1973

DateHigh TideLow TideSunMoonDate
AMftPMftAMftPMftRiseSet
1Sun4:237.77:518.311:53-3.35:149:18New Moon1Sun
2Mon5:267.38:288.312:336.212:41-2.75:159:18Waxing Crescent2Mon
3Tue6:296.79:048.31:375.61:28-1.75:159:17Waxing Crescent3Tue
4Wed7:366.09:398.32:464.72:14-0.55:169:17Waxing Crescent4Wed
5Thu8:495.310:128.13:553.83:000.95:179:17First Quarter5Thu
6Fri10:194.810:437.95:002.83:482.45:179:16First Quarter6Fri
7Sat12:244.76:001.84:393.95:189:16First Quarter7Sat
8Sun2:245.26:541.05:435.15:199:15First Quarter8Sun
9Mon3:506.07:430.37:036.15:209:15Waxing Gibbous9Mon
10Tue12:177.24:486.78:26-0.28:286.65:219:14Waxing Gibbous10Tue
11Wed12:537.05:317.29:06-0.69:396.85:229:13Waxing Gibbous11Wed
12Thu1:346.96:087.59:43-0.910:326.85:239:13Waxing Gibbous12Thu
13Fri2:216.86:407.610:19-1.011:116.75:249:12Full Moon13Fri
14Sat3:096.87:087.710:54-1.211:466.55:259:11Full Moon14Sat
15Sun3:576.77:327.711:28-1.25:269:10Full Moon15Sun
16Mon4:456.67:547.712:226.212:02-1.05:279:09Full Moon16Mon
17Tue5:336.48:147.81:005.812:36-0.85:289:08Waning Gibbous17Tue
18Wed6:236.18:357.81:415.31:11-0.35:299:07Waning Gibbous18Wed
19Thu7:175.88:597.82:254.61:450.55:309:06Waning Gibbous19Thu
20Fri8:175.39:257.83:103.72:211.45:329:05Waning Gibbous20Fri
21Sat9:275.09:537.83:562.82:572.65:339:04Third Quarter21Sat
22Sun10:534.810:227.74:451.83:373.85:349:03Third Quarter22Sun
23Mon12:555.05:360.74:245.05:359:02Third Quarter23Mon
24Tue3:035.76:31-0.35:346.05:369:01Third Quarter24Tue
25Wed4:116.47:27-1.27:056.75:389:00Waning Crescent25Wed
26Thu12:197.74:567.18:22-1.98:256.95:398:58Waning Crescent26Thu
27Fri1:167.75:347.59:15-2.49:316.75:408:57Waning Crescent27Fri
28Sat2:217.66:087.810:05-2.710:286.25:418:56New Moon28Sat
29Sun3:287.56:417.910:52-2.611:225.65:438:54New Moon29Sun
30Mon4:337.37:128.011:38-2.15:448:53New Moon30Mon
31Tue5:377.07:438.112:164.812:22-1.35:458:52Waxing Crescent31Tue
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