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 01m 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 - May 1923

DateHigh TideLow TideSunMoonDate
AMftPMftAMftPMftRiseSet
1Tue8:373.59:034.22:39-0.82:31-0.65:447:42Full Moon1Tue
2Wed9:283.59:534.13:29-0.73:16-0.65:437:43Waning Gibbous2Wed
3Thu10:193.310:443.94:20-0.64:02-0.45:427:44Waning Gibbous3Thu
4Fri11:123.111:393.65:13-0.34:50-0.15:407:45Waning Gibbous4Fri
5Sat12:082.96:15-0.15:490.25:397:46Waning Gibbous5Sat
6Sun12:373.21:072.87:200.17:190.45:387:47Third Quarter6Sun
7Mon1:362.92:082.68:220.38:400.55:377:48Third Quarter7Mon
8Tue2:382.73:122.69:190.49:480.65:367:49Third Quarter8Tue
9Wed3:422.64:162.610:100.410:470.65:347:50Third Quarter9Wed
10Thu4:432.55:122.710:550.411:360.55:337:51Waning Crescent10Thu
11Fri5:352.55:582.911:330.45:327:52Waning Crescent11Fri
12Sat6:182.66:383.012:190.412:060.35:317:53Waning Crescent12Sat
13Sun6:572.77:133.112:590.312:370.25:307:54Waning Crescent13Sun
14Mon7:332.77:463.21:380.21:070.15:297:55New Moon14Mon
15Tue8:082.88:183.32:150.11:390.15:287:56New Moon15Tue
16Wed8:432.88:513.32:510.12:130.15:277:57New Moon16Wed
17Thu9:192.79:263.23:230.12:490.15:267:58New Moon17Thu
18Fri9:572.710:043.23:520.13:250.25:257:59Waxing Crescent18Fri
19Sat10:392.710:463.14:210.24:050.25:248:00Waxing Crescent19Sat
20Sun11:242.611:333.04:570.34:490.35:238:01Waxing Crescent20Sun
21Mon12:152.65:410.35:400.45:238:02Waxing Crescent21Mon
22Tue12:253.01:102.76:360.36:420.55:228:03First Quarter22Tue
23Wed1:212.92:072.87:380.37:530.45:218:04First Quarter23Wed
24Thu2:212.93:093.08:430.29:170.35:208:05First Quarter24Thu
25Fri3:262.94:133.39:480.110:390.15:208:06Waxing Gibbous25Fri
26Sat4:343.05:153.610:47-0.111:44-0.15:198:06Waxing Gibbous26Sat
27Sun5:373.16:113.911:40-0.35:188:07Waxing Gibbous27Sun
28Mon6:343.37:034.112:41-0.312:31-0.45:188:08Full Moon28Mon
29Tue7:283.47:554.21:36-0.51:21-0.45:178:09Full Moon29Tue
30Wed8:203.48:464.22:28-0.52:11-0.45:168:10Full Moon30Wed
31Thu9:113.49:364.13:18-0.53:00-0.45:168:11Full Moon31Thu
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