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 (tomorrow) : 2:49 am (4.5 ft)
Next high tide : in 3h 10m at 9:02 pm (8.2 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 - Mar 2070

DateHigh TideLow TideSunMoonDate
AMftPMftAMftPMftRiseSet
1Sat7:127.68:216.11:003.31:461.86:525:56Waning Gibbous1Sat
2Sun7:417.49:325.91:444.12:321.66:505:58Waning Gibbous2Sun
3Mon8:147.111:125.92:334.93:211.56:486:00Third Quarter3Mon
4Tue8:526.83:335.64:161.56:466:01Third Quarter4Tue
5Wed12:526.19:37 AM6.64:516.15:151.46:446:03Third Quarter5Wed
6Thu2:016.410:31 AM6.46:186.26:151.36:426:04Third Quarter6Thu
7Fri2:466.711:33 AM6.37:306.17:101.16:406:06Waning Crescent7Fri
8Sat3:187.012:396.38:165.77:570.96:386:07Waning Crescent8Sat
9Sun4:427.12:426.59:495.29:390.77:367:09Waning Crescent9Sun
10Mon5:037.33:416.710:204.610:180.77:347:10Waning Crescent10Mon
11Tue5:247.54:376.910:533.810:570.97:327:12New Moon11Tue
12Wed5:477.65:317.011:292.911:351.37:307:13New Moon12Wed
13Thu6:147.86:267.112:081.97:287:15New Moon13Thu
14Fri6:447.97:237.112:161.912:511.07:267:16Waxing Crescent14Fri
15Sat7:177.98:236.912:582.71:380.37:247:18Waxing Crescent15Sat
16Sun7:527.89:296.81:443.62:28-0.27:227:20Waxing Crescent16Sun
17Mon8:317.610:476.62:354.43:22-0.47:197:21First Quarter17Mon
18Tue9:157.33:345.24:21-0.37:177:23First Quarter18Tue
19Wed12:156.710:07 AM6.94:485.75:25-0.17:157:24First Quarter19Wed
20Thu1:376.911:13 AM6.56:205.86:330.27:137:26First Quarter20Thu
21Fri2:417.112:326.27:555.57:400.47:117:27Waxing Gibbous21Fri
22Sat3:307.41:596.19:054.98:400.77:097:29Waxing Gibbous22Sat
23Sun4:117.53:186.29:524.19:321.17:077:30Waxing Gibbous23Sun
24Mon4:447.64:236.410:293.410:171.57:057:31Waxing Gibbous24Mon
25Tue5:137.65:196.611:022.710:582.07:037:33Full Moon25Tue
26Wed5:387.56:086.811:352.011:382.67:017:34Full Moon26Wed
27Thu6:007.46:546.812:081.46:597:36Full Moon27Thu
28Fri6:227.37:406.912:183.312:431.06:567:37Waning Gibbous28Fri
29Sat6:477.28:266.81:003.91:200.76:547:39Waning Gibbous29Sat
30Sun7:167.09:166.71:444.51:580.66:527:40Waning Gibbous30Sun
31Mon7:486.810:126.62:325.02:400.66:507:42Waning Gibbous31Mon
DateHigh TideLow TideSunMoonDate
AMftPMftAMftPMftRiseSet
Tidal Data Source: (9449834)

Common Questions About Roche Harbor, San Juan Island, WA Tides

Show All
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 11:55 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 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