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

TIDE TIMES for Saturday, July 18, 2026
The tide is currently falling in Roche Harbor, San Juan Island, WA.
Next low tide : in 3h 57m at 2:15 pm (0.0 ft)
Next high tide : 9:31 pm (8.1 ft)
Sunset today : 9:07 pm
Sunrise tomorrow : 5:30 am
Moon phase : Waxing Crescent (24% illuminated)
Tide Station Location : Station #9449834
Common Questions About Tides

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

DateHigh TideLow TideSunMoonDate
AMftPMftAMftPMftRiseSet
1Sun6:268.14:516.811:465.311:310.27:415:11New Moon1Sun
2Mon6:488.15:386.612:244.87:395:12Waxing Crescent2Mon
3Tue7:138.26:286.312:050.71:064.27:385:14Waxing Crescent3Tue
4Wed7:428.27:246.012:411.31:503.67:365:16Waxing Crescent4Wed
5Thu8:128.18:285.71:182.22:372.87:355:17Waxing Crescent5Thu
6Fri8:458.09:465.41:583.13:292.17:335:19First Quarter6Fri
7Sat9:217.911:325.52:434.14:251.37:325:21First Quarter7Sat
8Sun10:017.83:395.15:240.67:305:22First Quarter8Sun
9Mon1:286.010:48 AM7.74:565.96:24-0.27:295:24Waxing Gibbous9Mon
10Tue2:406.711:44 AM7.66:236.47:21-0.87:275:25Waxing Gibbous10Tue
11Wed3:297.312:477.67:396.38:14-1.27:255:27Waxing Gibbous11Wed
12Thu4:097.71:527.68:416.09:03-1.47:245:29Waxing Gibbous12Thu
13Fri4:458.12:567.69:355.49:50-1.37:225:30Full Moon13Fri
14Sat5:198.33:577.510:254.810:35-0.97:205:32Full Moon14Sat
15Sun5:528.44:567.311:144.111:19-0.27:195:34Full Moon15Sun
16Mon6:248.45:547.012:043.47:175:35Waning Gibbous16Mon
17Tue6:568.36:536.612:030.712:552.87:155:37Waning Gibbous17Tue
18Wed7:278.27:576.212:481.81:472.37:135:39Waning Gibbous18Wed
19Thu8:007.99:125.91:342.92:391.97:115:40Waning Gibbous19Thu
20Fri8:337.610:525.82:244.03:341.77:105:42Third Quarter20Fri
21Sat9:107.33:215.04:311.57:085:43Third Quarter21Sat
22Sun12:376.09:51 AM7.04:335.75:311.47:065:45Third Quarter22Sun
23Mon1:576.510:39 AM6.76:026.26:311.27:045:47Third Quarter23Mon
24Tue2:536.911:35 AM6.57:296.27:251.17:025:48Waning Crescent24Tue
25Wed3:347.212:366.58:306.08:110.97:005:50Waning Crescent25Wed
26Thu4:077.31:366.59:095.78:500.86:585:51Waning Crescent26Thu
27Fri4:337.42:306.69:395.49:260.76:565:53Waning Crescent27Fri
28Sat4:547.53:196.710:074.910:000.76:545:54New Moon28Sat
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 5:53 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 24% 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 Waxing Crescent (24% 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