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

TIDE TIMES for Tuesday, June 30, 2026
The tide is currently falling in Roche Harbor, San Juan Island, WA.
Next low tide : in 4h 36m at 11:45 am (-1.6 ft)
Next high tide : 8:10 pm (7.9 ft)
Sunset today : 9:18 pm
Sunrise tomorrow : 5:14 am
Moon phase : Full Moon (99% illuminated)
Tide Station Location : Station #9449834
Common Questions About Tides

Roche Harbor, San Juan Island, WA Tides - Sep 2045

DateHigh TideLow TideSunMoonDate
AMftPMftAMftPMftRiseSet
1Fri9:015.98:127.12:211.22:054.46:307:53Waning Gibbous1Fri
2Sat10:145.98:356.93:040.62:435.36:327:51Third Quarter2Sat
3Sun11:575.98:566.93:520.13:276.16:337:49Third Quarter3Sun
4Mon2:046.34:48-0.24:416.86:357:47Third Quarter4Mon
5Tue3:126.85:52-0.56:337.16:367:45Third Quarter5Tue
6Wed3:527.17:00-0.88:016.86:377:43Waning Crescent6Wed
7Thu4:227.38:04-1.08:576.26:397:41Waning Crescent7Thu
8Fri1:266.74:497.59:00-1.19:435.36:407:39Waning Crescent8Fri
9Sat2:466.95:147.69:50-1.010:274.26:427:37New Moon9Sat
10Sun4:007.05:397.710:36-0.411:112.96:437:35New Moon10Sun
11Mon5:107.06:037.811:200.511:551.76:447:33New Moon11Mon
12Tue6:167.06:287.812:031.66:467:30Waxing Crescent12Tue
13Wed7:227.06:557.812:410.612:472.96:477:28Waxing Crescent13Wed
14Thu8:306.97:237.61:27-0.21:354.26:497:26Waxing Crescent14Thu
15Fri9:466.87:547.32:15-0.62:305.36:507:24Waxing Crescent15Fri
16Sat11:126.88:276.93:05-0.73:376.16:517:22First Quarter16Sat
17Sun12:417.03:59-0.45:136.56:537:20First Quarter17Sun
18Mon1:577.24:590.07:466.46:547:18First Quarter18Mon
19Tue2:557.36:070.49:036.06:567:16First Quarter19Tue
20Wed3:397.47:180.79:405.66:577:14Waxing Gibbous20Wed
21Thu12:435.64:147.48:200.910:035.16:587:11Waxing Gibbous21Thu
22Fri2:065.74:417.39:091.110:214.57:007:09Waxing Gibbous22Fri
23Sat3:135.95:007.29:481.410:403.87:017:07Waxing Gibbous23Sat
24Sun4:096.15:127.110:231.811:023.07:037:05Full Moon24Sun
25Mon4:596.35:227.110:542.311:272.27:047:03Full Moon25Mon
26Tue5:466.55:377.111:263.011:551.37:067:01Full Moon26Tue
27Wed6:336.65:567.111:583.77:076:59Full Moon27Wed
28Thu7:226.86:187.112:250.512:334.57:086:57Waning Gibbous28Thu
29Fri8:146.96:407.012:59-0.11:115.37:106:55Waning Gibbous29Fri
30Sat9:136.97:006.91:37-0.61:536.07:116:52Waning Gibbous30Sat
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 3:57 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 99% 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 Full Moon (99% 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