Tides Today & Tomorrow in Block Island, RI

TIDE TIMES for Friday, August 21, 2026
The tide is currently rising in Block Island, RI.
Next low tide : 10:17 pm (0.9 ft)
Next high tide : in 2h 31m at 3:23 pm (2.6 ft)
Sunset today : 7:36 pm
Sunrise tomorrow : 6:02 am
Moon phase : First Quarter (65% illuminated)
Tide Station Location : Station #8459338
Common Questions About Tides

Block Island, RI Tides - Jun 1923

DateHigh TideLow TideSunMoonDate
AMftPMftAMftPMftRiseSet
1Fri10:023.310:273.84:07-0.43:48-0.25:158:11Waning Gibbous1Fri
2Sat10:543.211:183.54:56-0.24:360.05:158:12Waning Gibbous2Sat
3Sun11:473.05:480.05:310.35:158:13Waning Gibbous3Sun
4Mon12:113.212:432.96:430.26:460.55:148:14Third Quarter4Mon
5Tue1:052.91:382.87:370.38:020.65:148:14Third Quarter5Tue
6Wed1:582.72:342.78:260.49:070.75:138:15Third Quarter6Wed
7Thu2:532.53:322.79:120.510:060.75:138:16Third Quarter7Thu
8Fri3:522.44:292.79:540.510:590.75:138:16Waning Crescent8Fri
9Sat4:492.45:192.810:340.511:460.65:138:17Waning Crescent9Sat
10Sun5:382.46:023.011:130.45:138:17Waning Crescent10Sun
11Mon6:212.56:393.112:300.411:50 AM0.35:128:18Waning Crescent11Mon
12Tue7:002.67:143.21:120.312:280.35:128:18New Moon12Tue
13Wed7:382.77:493.31:540.21:070.25:128:19New Moon13Wed
14Thu8:162.88:263.42:330.21:470.15:128:19New Moon14Thu
15Fri8:552.89:053.43:090.12:270.15:128:20New Moon15Fri
16Sat9:362.99:463.43:410.13:080.15:128:20Waxing Crescent16Sat
17Sun10:202.910:293.34:110.13:500.25:128:21Waxing Crescent17Sun
18Mon11:062.911:163.34:450.24:350.25:128:21Waxing Crescent18Mon
19Tue11:573.05:250.25:280.35:128:21Waxing Crescent19Tue
20Wed12:083.212:513.06:140.26:300.45:138:22First Quarter20Wed
21Thu1:023.11:473.17:090.27:440.45:138:22First Quarter21Thu
22Fri2:003.02:463.38:080.19:100.45:138:22First Quarter22Fri
23Sat3:022.93:503.49:100.110:290.25:138:22Waxing Gibbous23Sat
24Sun4:102.94:543.610:140.011:340.15:138:22Waxing Gibbous24Sun
25Mon5:173.05:533.811:16-0.15:148:22Waxing Gibbous25Mon
26Tue6:163.16:484.012:31-0.112:12-0.25:148:23Waxing Gibbous26Tue
27Wed7:113.27:404.01:25-0.21:06-0.25:148:23Full Moon27Wed
28Thu8:043.38:314.02:16-0.31:59-0.25:158:23Full Moon28Thu
29Fri8:553.39:203.93:04-0.32:49-0.25:158:23Full Moon29Fri
30Sat9:443.310:073.73:48-0.33:35-0.15:168:23Waning Gibbous30Sat
DateHigh TideLow TideSunMoonDate
AMftPMftAMftPMftRiseSet
Tidal Data Source: (8459338)

Common Questions About Block Island, RI Tides

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What time does the tide turn (slack tide) in Block Island, RI today?

Slack tide in Block Island, RI is approximately 6:50 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 Block Island, RI?

Block Island, RI is currently in a transitional phase. Tonight's moon is 65% 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 Block Island, RI 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 Block Island, RI?

Tide predictions for Block Island, RI 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 Block Island, RI?

Tide data for Block Island, RI is sourced from NOAA Station #8459338. View the official NOAA station page at https://tidesandcurrents.noaa.gov/stationhome.html?id=8459338.

What is the moon phase in Block Island, RI tonight?

Tonight the moon over Block Island, RI is First Quarter (65% illuminated). This places Block Island, RI 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