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

TIDE TIMES for Saturday, July 18, 2026
The tide is currently rising in Roche Harbor, San Juan Island, WA.
Next low tide : 2:15 pm (0.0 ft)
Next high tide : in 2h 49m at 7:42 am (5.9 ft)
Sunset today : 9:07 pm
Sunrise tomorrow : 5:30 am
Moon phase : Waxing Crescent (24% illuminated)
Tide Station Location : Station #9449834
Common Questions About Tides

Roche Harbor, San Juan Island, WA Tides - Nov 2070

DateHigh TideLow TideSunMoonDate
AMftPMftAMftPMftRiseSet
1Sat5:246.94:077.510:144.410:480.28:005:52New Moon1Sat
2Sun5:127.33:317.39:594.910:19-0.37:014:50New Moon2Sun
3Mon5:567.63:577.210:435.410:51-0.57:034:49New Moon3Mon
4Tue6:387.84:267.011:305.711:25-0.67:044:47New Moon4Tue
5Wed7:197.84:596.812:196.07:064:46Waxing Crescent5Wed
6Thu7:597.85:356.512:01-0.51:166.17:074:44Waxing Crescent6Thu
7Fri8:427.86:146.212:39-0.22:226.27:094:43Waxing Crescent7Fri
8Sat9:257.77:005.81:210.23:406.07:114:41Waxing Crescent8Sat
9Sun10:107.77:575.42:050.75:085.77:124:40First Quarter9Sun
10Mon10:527.69:095.02:521.36:115.17:144:38First Quarter10Mon
11Tue11:307.610:334.83:451.96:444.47:154:37First Quarter11Tue
12Wed12:047.64:432.57:093.67:174:36First Quarter12Wed
13Thu12:054.912:377.75:453.27:362.67:184:35Waxing Gibbous13Thu
14Fri1:365.41:097.76:443.88:051.47:204:33Waxing Gibbous14Fri
15Sat2:506.01:427.87:394.38:380.27:214:32Waxing Gibbous15Sat
16Sun3:486.82:168.08:314.89:14-0.97:234:31Full Moon16Sun
17Mon4:407.42:528.09:205.39:54-1.87:244:30Full Moon17Mon
18Tue5:307.93:318.010:095.710:36-2.47:264:29Full Moon18Tue
19Wed6:198.34:147.911:016.011:21-2.67:274:28Waning Gibbous19Wed
20Thu7:088.55:017.611:586.27:294:27Waning Gibbous20Thu
21Fri7:588.65:537.112:08-2.41:036.27:304:26Waning Gibbous21Fri
22Sat8:508.66:536.512:58-1.82:195.97:324:25Waning Gibbous22Sat
23Sun9:418.58:035.81:50-0.93:485.37:334:24Third Quarter23Sun
24Mon10:328.49:305.22:450.25:194.57:354:23Third Quarter24Mon
25Tue11:198.311:244.93:441.56:303.57:364:22Third Quarter25Tue
26Wed12:028.24:472.77:202.47:374:22Waning Crescent26Wed
27Thu1:195.312:408.05:543.87:581.57:394:21Waning Crescent27Thu
28Fri2:426.01:137.97:014.78:300.77:404:20Waning Crescent28Fri
29Sat3:456.71:437.78:025.48:590.17:414:20Waning Crescent29Sat
30Sun4:357.32:117.58:575.99:27-0.47:434:19New Moon30Sun
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 10:58 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 transitional phase. Tonight's moon is 24% 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 Waxing Crescent (24% 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