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

TIDE TIMES for Thursday, July 30, 2026
The tide is currently falling in Roche Harbor, San Juan Island, WA.
Next low tide : in 3h 19m at 12:01 pm (-1.0 ft)
Next high tide : 7:46 pm (7.7 ft)
Sunset today : 8:53 pm
Sunrise tomorrow : 5:44 am
Moon phase : Full Moon (99% illuminated)
Tide Station Location : Station #9449834
Common Questions About Tides

Roche Harbor, San Juan Island, WA Tides - Jan 1978

DateHigh TideLow TideSunMoonDate
AMftPMftAMftPMftRiseSet
1Sun9:418.39:364.92:232.04:323.88:044:27Third Quarter1Sun
2Mon10:168.311:164.93:083.05:222.88:044:28Third Quarter2Mon
3Tue10:528.24:034.16:101.68:044:29Third Quarter3Tue
4Wed1:215.411:31 AM8.25:105.16:580.48:044:30Waning Crescent4Wed
5Thu2:486.212:138.26:265.97:44-0.78:044:31Waning Crescent5Thu
6Fri3:457.012:598.37:366.38:29-1.68:044:32Waning Crescent6Fri
7Sat4:317.71:498.38:396.59:15-2.28:034:34New Moon7Sat
8Sun5:138.32:438.29:366.510:00-2.58:034:35New Moon8Sun
9Mon5:538.63:398.010:326.210:46-2.48:034:36New Moon9Mon
10Tue6:328.84:367.711:295.911:32-1.98:024:37Waxing Crescent10Tue
11Wed7:118.95:347.212:295.48:024:39Waxing Crescent11Wed
12Thu7:498.96:346.612:18-1.11:324.88:014:40Waxing Crescent12Thu
13Fri8:278.87:405.91:040.02:374.18:014:41Waxing Crescent13Fri
14Sat9:058.68:595.31:511.33:433.48:004:43First Quarter14Sat
15Sun9:428.410:505.12:402.64:472.77:594:44First Quarter15Sun
16Mon10:188.13:333.95:472.07:584:45First Quarter16Mon
17Tue12:545.410:55 AM7.84:365.16:411.47:584:47First Quarter17Tue
18Wed2:256.111:34 AM7.65:546.07:270.97:574:48Waxing Gibbous18Wed
19Thu3:276.812:147.47:166.58:070.47:564:50Waxing Gibbous19Thu
20Fri4:127.312:577.28:266.78:430.17:554:51Waxing Gibbous20Fri
21Sat4:497.71:427.29:196.79:17-0.17:544:53Waxing Gibbous21Sat
22Sun5:207.92:277.19:596.69:50-0.37:534:54Full Moon22Sun
23Mon5:478.03:127.110:356.410:23-0.47:524:56Full Moon23Mon
24Tue6:108.13:567.011:106.110:56-0.37:514:57Full Moon24Tue
25Wed6:328.14:416.911:465.811:30-0.17:504:59Full Moon25Wed
26Thu6:548.25:286.612:255.37:495:01Waning Gibbous26Thu
27Fri7:198.36:176.312:050.31:074.87:485:02Waning Gibbous27Fri
28Sat7:478.37:126.012:410.91:514.17:475:04Waning Gibbous28Sat
29Sun8:188.28:155.61:181.72:393.47:455:05Waning Gibbous29Sun
30Mon8:518.29:325.31:582.73:312.67:445:07Third Quarter30Mon
31Tue9:268.111:155.32:423.74:261.77:435:09Third Quarter31Tue
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 3:53 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 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