Tides Today & Tomorrow in Block Island, RI

TIDE TIMES for Monday, August 17, 2026
The tide is currently rising in Block Island, RI.
Next low tide (tomorrow) : 5:28 am (0.4 ft)
Next high tide : in 3h 57m at 11:58 pm (2.7 ft)
Sunset today : 7:42 pm
Sunrise tomorrow : 5:58 am
Moon phase : Waxing Crescent (27% illuminated)
Tide Station Location : Station #8459338
Common Questions About Tides

Block Island, RI Tides - Sep 1931

DateHigh TideLow TideSunMoonDate
AMftPMftAMftPMftRiseSet
1Tue10:453.011:032.74:090.34:410.66:117:21Waning Gibbous1Tue
2Wed11:203.011:432.54:400.45:190.76:127:19Waning Gibbous2Wed
3Thu12:002.95:160.56:070.86:137:17Third Quarter3Thu
4Fri12:292.412:472.85:590.67:110.96:147:16Third Quarter4Fri
5Sat1:212.31:422.86:520.79:030.96:157:14Third Quarter5Sat
6Sun2:212.22:462.87:550.710:240.86:167:12Third Quarter6Sun
7Mon3:302.34:013.09:080.611:190.66:177:11Waning Crescent7Mon
8Tue4:422.55:103.210:260.46:187:09Waning Crescent8Tue
9Wed5:422.96:063.512:050.411:34 AM0.26:197:07Waning Crescent9Wed
10Thu6:343.26:563.812:460.112:31-0.16:207:06New Moon10Thu
11Fri7:233.67:453.91:26-0.21:26-0.36:217:04New Moon11Fri
12Sat8:113.98:323.92:04-0.42:19-0.46:227:02New Moon12Sat
13Sun8:594.19:203.82:42-0.43:10-0.56:237:00New Moon13Sun
14Mon9:474.210:083.53:19-0.44:01-0.36:246:59Waxing Crescent14Mon
15Tue10:374.110:593.23:57-0.34:55-0.16:256:57Waxing Crescent15Tue
16Wed11:303.911:532.94:37-0.16:000.26:266:55Waxing Crescent16Wed
17Thu12:283.65:230.27:180.46:276:54First Quarter17Thu
18Fri12:522.71:313.36:210.48:340.66:286:52First Quarter18Fri
19Sat1:562.52:423.17:540.69:440.76:296:50First Quarter19Sat
20Sun3:072.43:572.99:340.710:450.76:306:48First Quarter20Sun
21Mon4:202.55:042.910:460.611:350.66:316:47Waxing Gibbous21Mon
22Tue5:222.65:563.011:410.66:326:45Waxing Gibbous22Tue
23Wed6:112.86:383.112:160.512:250.56:336:43Waxing Gibbous23Wed
24Thu6:533.07:153.112:510.41:040.46:346:42Waxing Gibbous24Thu
25Fri7:313.17:493.11:210.31:390.36:366:40Full Moon25Fri
26Sat8:043.38:203.11:470.22:120.36:376:38Full Moon26Sat
27Sun7:353.37:513.01:100.11:430.35:385:37Full Moon27Sun
28Mon8:043.38:222.91:340.12:130.35:395:35Full Moon28Mon
29Tue8:343.38:552.82:000.22:420.45:405:33Waning Gibbous29Tue
30Wed9:063.29:322.62:300.33:130.55:415:31Waning Gibbous30Wed
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 2:43 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 Block Island, RI?

Block Island, RI is currently in a transitional phase. Tonight's moon is 27% 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 Waxing Crescent (27% 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