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

TIDE TIMES for Sunday, July 19, 2026
The tide is currently rising in Roche Harbor, San Juan Island, WA.
Next low tide : 2:59 pm (1.5 ft)
Next high tide : in 4h 29m at 8:57 am (5.2 ft)
Sunset today : 9:06 pm
Sunrise tomorrow : 5:31 am
Moon phase : First Quarter (33% illuminated)
Tide Station Location : Station #9449834
Common Questions About Tides

Roche Harbor, San Juan Island, WA Tides - Jun 2071

DateHigh TideLow TideSunMoonDate
AMftPMftAMftPMftRiseSet
1Mon6:307.09:258.21:335.81:36-2.55:149:06Waxing Crescent1Mon
2Tue7:276.510:148.22:425.62:27-1.85:139:07Waxing Crescent2Tue
3Wed8:325.911:028.24:015.13:20-0.85:139:08First Quarter3Wed
4Thu9:485.211:498.15:244.44:150.45:129:09First Quarter4Thu
5Fri11:244.76:423.45:141.65:129:10First Quarter5Fri
6Sat12:338.01:224.77:432.46:172.85:119:11First Quarter6Sat
7Sun1:147.83:035.28:311.47:233.95:119:12Waxing Gibbous7Sun
8Mon1:517.74:165.99:090.58:284.75:109:12Waxing Gibbous8Mon
9Tue2:257.55:146.69:43-0.29:275.35:109:13Waxing Gibbous9Tue
10Wed2:577.36:027.110:14-0.710:215.75:109:14Full Moon10Wed
11Thu3:287.26:447.510:46-1.111:106.05:109:14Full Moon11Thu
12Fri4:017.07:227.711:18-1.311:586.15:099:15Full Moon12Fri
13Sat4:366.87:587.811:52-1.35:099:16Full Moon13Sat
14Sun5:156.68:317.812:476.112:28-1.25:099:16Waning Gibbous14Sun
15Mon5:566.49:037.81:396.01:05-0.95:099:16Waning Gibbous15Mon
16Tue6:396.19:347.82:345.81:43-0.55:099:17Waning Gibbous16Tue
17Wed7:275.710:057.73:325.52:220.05:099:17Waning Gibbous17Wed
18Thu8:205.210:367.74:305.13:020.75:099:18Waning Gibbous18Thu
19Fri9:234.811:087.75:234.53:431.55:099:18Third Quarter19Fri
20Sat10:384.511:427.66:113.74:282.35:109:18Third Quarter20Sat
21Sun12:084.46:542.85:203.35:109:18Third Quarter21Sun
22Mon12:167.61:594.77:331.86:224.15:109:19Waning Crescent22Mon
23Tue12:517.63:345.48:120.77:284.95:109:19Waning Crescent23Tue
24Wed1:287.64:366.18:51-0.58:315.45:119:19Waning Crescent24Wed
25Thu2:077.75:256.89:32-1.59:305.85:119:19Waning Crescent25Thu
26Fri2:507.86:097.410:14-2.310:245.95:129:19New Moon26Fri
27Sat3:387.86:517.810:58-2.911:195.95:129:19New Moon27Sat
28Sun4:297.77:338.111:44-3.05:139:19New Moon28Sun
29Mon5:257.48:148.312:155.812:31-2.85:139:18Waxing Crescent29Mon
30Tue6:237.08:568.41:175.41:19-2.25:149:18Waxing Crescent30Tue
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 11:58 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 transitional phase. Tonight's moon is 33% 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 First Quarter (33% 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