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

TIDE TIMES for Monday, August 3, 2026
The tide is currently falling in Roche Harbor, San Juan Island, WA.
Next low tide : in 5h 27m at 2:18 pm (1.9 ft)
Next high tide : 9:11 pm (7.7 ft)
Sunset today : 8:47 pm
Sunrise tomorrow : 5:50 am
Moon phase : Waning Gibbous (74% illuminated)
Tide Station Location : Station #9449834
Common Questions About Tides

Roche Harbor, San Juan Island, WA Tides - Aug 1970

DateHigh TideLow TideSunMoonDate
AMftPMftAMftPMftRiseSet
1Sat3:236.67:067.711:02-1.111:566.25:468:51New Moon1Sat
2Sun4:156.67:307.611:38-0.95:488:49New Moon2Sun
3Mon5:036.57:497.612:285.812:12-0.65:498:48New Moon3Mon
4Tue5:516.38:067.51:045.312:460.05:508:46Waxing Crescent4Tue
5Wed6:416.08:227.51:434.61:180.75:528:45Waxing Crescent5Wed
6Thu7:355.68:427.52:233.91:501.65:538:43Waxing Crescent6Thu
7Fri8:355.39:047.43:043.12:222.65:548:41Waxing Crescent7Fri
8Sat9:455.09:297.33:462.32:543.85:568:40First Quarter8Sat
9Sun11:195.09:547.24:301.53:254.95:578:38First Quarter9Sun
10Mon2:155.45:180.74:005.95:588:36First Quarter10Mon
11Tue4:016.26:120.05:286.76:008:35First Quarter11Tue
12Wed4:356.87:10-0.77:227.26:018:33Waxing Gibbous12Wed
13Thu5:047.28:07-1.38:387.26:038:31Waxing Gibbous13Thu
14Fri12:457.35:327.59:02-1.99:326.96:048:30Waxing Gibbous14Fri
15Sat1:587.45:597.79:52-2.310:206.36:058:28Full Moon15Sat
16Sun3:107.46:267.810:40-2.311:085.56:078:26Full Moon16Sun
17Mon4:207.46:527.911:25-1.911:584.46:088:24Full Moon17Mon
18Tue5:277.27:188.012:08-1.16:108:22Waning Gibbous18Tue
19Wed6:346.87:458.012:503.312:510.16:118:20Waning Gibbous19Wed
20Thu7:446.48:128.01:432.11:351.66:128:19Waning Gibbous20Thu
21Fri9:006.08:417.82:371.12:203.16:148:17Waning Gibbous21Fri
22Sat10:335.89:127.63:320.33:114.56:158:15Third Quarter22Sat
23Sun12:256.04:28-0.14:135.76:178:13Third Quarter23Sun
24Mon2:086.55:28-0.35:446.56:188:11Third Quarter24Mon
25Tue3:207.06:31-0.38:016.86:198:09Waning Crescent25Tue
26Wed4:117.47:35-0.39:426.56:218:07Waning Crescent26Wed
27Thu12:236.24:517.58:35-0.210:246.26:228:05Waning Crescent27Thu
28Fri1:376.25:257.59:25-0.210:465.86:248:03Waning Crescent28Fri
29Sat2:446.25:527.410:07-0.111:045.46:258:01Waning Crescent29Sat
30Sun3:416.36:147.310:430.111:264.86:267:59New Moon30Sun
31Mon4:316.36:297.311:150.511:534.26:287:57New Moon31Mon
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 5:44 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 74% 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 Waning Gibbous (74% 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