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

TIDE TIMES for Friday, July 17, 2026
The tide is currently rising in Roche Harbor, San Juan Island, WA.
Next low tide : 1:31 pm (-1.3 ft)
Next high tide : in 4h 07m at 6:35 am (6.6 ft)
Sunset today : 9:08 pm
Sunrise tomorrow : 5:28 am
Moon phase : Waxing Crescent (15% illuminated)
Tide Station Location : Station #9449834
Common Questions About Tides

Roche Harbor, San Juan Island, WA Tides - Jul 1990

DateHigh TideLow TideSunMoonDate
AMftPMftAMftPMftRiseSet
1Sun3:155.37:321.16:135.45:149:18First Quarter1Sun
2Mon12:057.34:306.18:100.47:346.35:159:18Waxing Gibbous2Mon
3Tue12:327.15:206.98:46-0.38:546.85:159:17Waxing Gibbous3Tue
4Wed1:047.05:597.39:21-0.710:007.15:169:17Waxing Gibbous4Wed
5Thu1:416.96:337.69:56-1.110:497.15:179:17Waxing Gibbous5Thu
6Fri2:246.97:037.810:31-1.411:277.15:179:16Full Moon6Fri
7Sat3:116.97:317.811:07-1.65:189:16Full Moon7Sat
8Sun3:596.87:567.912:036.911:43 AM-1.75:199:15Full Moon8Sun
9Mon4:486.78:207.912:406.712:19-1.65:209:15Full Moon9Mon
10Tue5:386.58:448.01:236.312:56-1.45:219:14Waning Gibbous10Tue
11Wed6:336.19:088.02:095.71:33-0.85:229:13Waning Gibbous11Wed
12Thu7:345.79:338.02:584.92:100.15:239:13Waning Gibbous12Thu
13Fri8:445.29:598.03:483.82:491.25:249:12Third Quarter13Fri
14Sat10:064.810:278.04:382.63:292.65:259:11Third Quarter14Sat
15Sun11:544.710:567.95:291.44:134.05:269:10Third Quarter15Sun
16Mon2:175.26:220.15:095.45:279:09Third Quarter16Mon
17Tue3:546.17:16-1.06:306.55:289:08Waning Crescent17Tue
18Wed12:057.94:517.08:09-1.97:587.15:299:08Waning Crescent18Wed
19Thu12:527.85:347.59:01-2.59:127.25:309:07Waning Crescent19Thu
20Fri1:487.76:127.99:51-2.910:147.05:319:05New Moon20Fri
21Sat2:517.66:478.010:39-2.911:106.55:339:04New Moon21Sat
22Sun3:567.47:218.111:25-2.65:349:03New Moon22Sun
23Mon4:597.17:538.112:046.012:10-2.05:359:02New Moon23Mon
24Tue5:596.78:228.01:005.312:52-1.15:369:01Waxing Crescent24Tue
25Wed7:006.18:497.91:564.51:340.05:379:00Waxing Crescent25Wed
26Thu8:045.69:147.82:523.72:151.25:398:59Waxing Crescent26Thu
27Fri9:185.19:377.63:452.82:572.65:408:57First Quarter27Fri
28Sat10:574.910:027.44:372.13:414.05:418:56First Quarter28Sat
29Sun1:165.15:281.44:335.25:438:55First Quarter29Sun
30Mon3:075.86:190.95:496.15:448:53First Quarter30Mon
31Tue4:136.57:110.47:296.75:458:52Waxing Gibbous31Tue
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 10:03 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 spring phase. Tonight's moon is 15% 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 Waxing Crescent (15% 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