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

TIDE TIMES for Thursday, July 9, 2026
The tide is currently rising in Roche Harbor, San Juan Island, WA.
Next low tide : 5:57 pm (5.8 ft)
Next high tide : in 6h 19m at 3:25 pm (5.5 ft)
Sunset today : 9:15 pm
Sunrise tomorrow : 5:20 am
Moon phase : Waning Crescent (28% illuminated)
Tide Station Location : Station #9449834
Common Questions About Tides

Roche Harbor, San Juan Island, WA Tides - Dec 1999

DateHigh TideLow TideSunMoonDate
AMftPMftAMftPMftRiseSet
1Wed12:208.34:482.27:383.17:434:19Third Quarter1Wed
2Thu1:015.012:578.15:543.38:112.17:444:19Waning Crescent2Thu
3Fri2:315.71:287.96:584.38:391.37:464:18Waning Crescent3Fri
4Sat3:376.41:537.77:575.09:040.67:474:18Waning Crescent4Sat
5Sun4:307.02:167.68:505.79:290.07:484:18Waning Crescent5Sun
6Mon5:157.52:407.49:396.19:56-0.57:494:17New Moon6Mon
7Tue5:557.93:077.310:256.510:25-0.87:504:17New Moon7Tue
8Wed6:328.13:387.211:116.710:57-0.97:514:17New Moon8Wed
9Thu7:078.24:127.012:006.87:524:17New Moon9Thu
10Fri7:418.34:486.712:546.87:534:17Waxing Crescent10Fri
11Sat8:158.35:256.412:07-0.71:546.77:544:16Waxing Crescent11Sat
12Sun8:508.36:076.112:45-0.43:026.57:554:16Waxing Crescent12Sun
13Mon9:268.37:015.61:260.04:136.07:564:17Waxing Crescent13Mon
14Tue10:028.38:155.22:080.65:095.47:574:17First Quarter14Tue
15Wed10:388.39:424.82:541.45:474.67:584:17First Quarter15Wed
16Thu11:128.211:204.83:452.26:213.57:584:17First Quarter16Thu
17Fri11:478.24:433.26:562.37:594:17Waxing Gibbous17Fri
18Sat1:115.212:218.25:494.27:330.98:004:18Waxing Gibbous18Sat
19Sun2:436.012:578.36:555.08:12-0.48:014:18Waxing Gibbous19Sun
20Mon3:486.91:348.47:575.78:53-1.68:014:18Waxing Gibbous20Mon
21Tue4:417.62:158.48:556.29:35-2.58:024:19Full Moon21Tue
22Wed5:298.32:598.39:506.510:19-2.98:024:19Full Moon22Wed
23Thu6:158.73:478.110:466.711:05-3.08:034:20Full Moon23Thu
24Fri7:008.94:397.811:466.611:52-2.68:034:20Waning Gibbous24Fri
25Sat7:459.05:347.312:516.48:034:21Waning Gibbous25Sat
26Sun8:308.96:336.612:40-1.82:055.98:044:22Waning Gibbous26Sun
27Mon9:148.87:405.91:29-0.83:255.38:044:22Third Quarter27Mon
28Tue9:578.79:025.22:190.54:464.48:044:23Third Quarter28Tue
29Wed10:388.510:584.83:111.85:563.58:044:24Third Quarter29Wed
30Thu11:168.24:083.26:492.58:044:25Third Quarter30Thu
31Fri1:075.111:50 AM8.05:114.47:351.68:044:26Waning 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 4:41 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 transitional phase. Tonight's moon is 28% 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 shifting between spring and neap.

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 Crescent (28% illuminated). This places Roche Harbor, San Juan Island, WA in a transitional tide cycle, so tidal ranges are shifting between spring and neap 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