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

TIDE TIMES for Thursday, July 30, 2026
The tide is currently rising in Roche Harbor, San Juan Island, WA.
Next low tide (tomorrow) : 12:53 am (5.6 ft)
Next high tide : in 4h 09m at 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 - May 1977

DateHigh TideLow TideSunMoonDate
AMftPMftAMftPMftRiseSet
1Sun3:207.54:456.59:540.69:543.45:528:27Waxing Gibbous1Sun
2Mon3:547.65:437.110:33-0.610:424.05:508:28Full Moon2Mon
3Tue4:307.76:377.511:14-1.611:314.65:488:30Full Moon3Tue
4Wed5:087.77:317.811:58-2.25:478:31Full Moon4Wed
5Thu5:507.68:268.012:235.012:45-2.55:458:32Waning Gibbous5Thu
6Fri6:357.49:228.01:215.41:34-2.35:438:34Waning Gibbous6Fri
7Sat7:246.910:207.92:275.62:25-1.85:428:35Waning Gibbous7Sat
8Sun8:196.311:187.93:435.53:20-1.05:408:37Third Quarter8Sun
9Mon9:255.75:125.14:170.05:398:38Third Quarter9Mon
10Tue12:147.810:47 AM5.16:464.45:181.05:378:39Third Quarter10Tue
11Wed1:057.712:334.87:563.66:232.05:368:41Third Quarter11Wed
12Thu1:507.62:235.08:452.77:272.95:358:42Waning Crescent12Thu
13Fri2:277.53:455.59:211.88:283.75:338:44Waning Crescent13Fri
14Sat2:587.34:476.19:501.19:224.45:328:45Waning Crescent14Sat
15Sun3:237.25:376.610:170.410:104.95:318:46Waning Crescent15Sun
16Mon3:467.16:217.010:44-0.110:555.35:298:48New Moon16Mon
17Tue4:117.07:017.211:13-0.611:385.65:288:49New Moon17Tue
18Wed4:396.97:377.411:44-0.85:278:50New Moon18Wed
19Thu5:116.78:137.512:225.812:17-1.05:268:51New Moon19Thu
20Fri5:466.68:487.61:096.012:53-0.95:258:53Waxing Crescent20Fri
21Sat6:236.39:247.62:016.01:30-0.85:238:54Waxing Crescent21Sat
22Sun7:036.010:027.62:596.02:10-0.55:228:55Waxing Crescent22Sun
23Mon7:485.710:417.64:025.82:53-0.15:218:56Waxing Crescent23Mon
24Tue8:435.311:197.65:075.43:380.55:208:58First Quarter24Tue
25Wed9:544.911:577.66:044.84:271.15:198:59First Quarter25Wed
26Thu11:184.66:504.05:221.95:189:00First Quarter26Thu
27Fri12:337.612:524.67:302.96:222.85:189:01First Quarter27Fri
28Sat1:097.62:325.18:091.77:253.65:179:02Waxing Gibbous28Sat
29Sun1:457.73:555.88:480.48:264.35:169:03Waxing Gibbous29Sun
30Mon2:227.84:586.69:28-0.99:234.95:159:04Waxing Gibbous30Mon
31Tue3:027.95:527.210:10-2.010:185.35:149:05Full Moon31Tue
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 10:19 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