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 3h 53m 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 - Aug 1923

DateHigh TideLow TideSunMoonDate
AMftPMftAMftPMftRiseSet
1Wed11:323.011:472.94:560.25:100.55:408:04Waning Gibbous1Wed
2Thu12:152.95:260.35:560.75:418:03Waning Gibbous2Thu
3Fri12:292.712:572.86:030.56:590.85:428:02Third Quarter3Fri
4Sat1:132.51:392.76:470.68:210.95:438:00Third Quarter4Sat
5Sun1:592.42:262.77:360.69:350.95:447:59Third Quarter5Sun
6Mon2:522.33:222.78:300.710:380.85:457:58Third Quarter6Mon
7Tue3:562.34:262.89:300.611:300.75:467:57Waning Crescent7Tue
8Wed4:592.45:233.010:330.55:477:56Waning Crescent8Wed
9Thu5:512.66:113.212:160.511:30 AM0.45:487:54Waning Crescent9Thu
10Fri6:372.86:553.412:590.312:200.25:497:53Waning Crescent10Fri
11Sat7:213.17:383.61:380.11:080.05:507:52New Moon11Sat
12Sun8:053.38:223.72:150.01:55-0.15:517:50New Moon12Sun
13Mon8:503.59:073.72:49-0.12:42-0.25:527:49New Moon13Mon
14Tue9:373.69:533.73:23-0.23:29-0.25:537:48Waxing Crescent14Tue
15Wed10:243.710:423.63:59-0.24:17-0.15:547:46Waxing Crescent15Wed
16Thu11:153.711:333.44:38-0.25:100.05:557:45Waxing Crescent16Thu
17Fri12:103.65:22-0.16:170.25:567:44First Quarter17Fri
18Sat12:283.21:073.66:150.17:430.35:577:42First Quarter18Sat
19Sun1:273.02:083.57:180.29:030.45:587:41First Quarter19Sun
20Mon2:302.83:153.48:360.310:130.45:597:39First Quarter20Mon
21Tue3:402.84:263.410:010.311:140.36:007:38Waxing Gibbous21Tue
22Wed4:502.95:303.511:100.26:017:36Waxing Gibbous22Wed
23Thu5:513.06:243.512:070.212:070.26:027:35Waxing Gibbous23Thu
24Fri6:443.27:133.612:550.112:570.16:037:33Full Moon24Fri
25Sat7:313.37:573.61:380.01:430.16:047:32Full Moon25Sat
26Sun8:163.48:383.52:160.02:240.16:057:30Full Moon26Sun
27Mon8:573.49:173.42:490.03:000.16:067:29Full Moon27Mon
28Tue9:363.39:543.33:170.03:310.26:077:27Waning Gibbous28Tue
29Wed10:133.210:303.13:420.14:010.36:087:25Waning Gibbous29Wed
30Thu10:493.111:082.94:080.24:330.56:097:24Waning Gibbous30Thu
31Fri11:263.011:472.74:390.35:120.66:107:22Waning Gibbous31Fri
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