Tides Today & Tomorrow in Block Island, RI

TIDE TIMES for Friday, August 21, 2026
The tide is currently falling in Block Island, RI.
Next low tide : in 43m at 10:17 pm (0.9 ft)
Next high tide (tomorrow) : 3:42 am (2.1 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 - Sep 1922

DateHigh TideLow TideSunMoonDate
AMftPMftAMftPMftRiseSet
1Fri4:352.75:153.110:580.511:460.56:127:20Waxing Gibbous1Fri
2Sat5:342.86:073.211:510.46:137:19Waxing Gibbous2Sat
3Sun6:242.96:513.212:300.412:350.46:147:17Waxing Gibbous3Sun
4Mon7:073.07:313.21:070.31:150.36:157:15Full Moon4Mon
5Tue7:473.18:073.31:410.21:510.36:167:14Full Moon5Tue
6Wed8:233.28:413.22:110.22:230.26:177:12Full Moon6Wed
7Thu8:563.29:133.22:370.12:540.36:187:10Full Moon7Thu
8Fri9:283.29:453.13:010.13:230.36:197:09Waning Gibbous8Fri
9Sat10:003.110:192.93:280.23:540.46:207:07Waning Gibbous9Sat
10Sun10:333.110:562.83:580.34:280.56:217:05Waning Gibbous10Sun
11Mon11:113.011:382.64:320.45:060.66:227:04Waning Gibbous11Mon
12Tue11:542.95:110.55:540.86:237:02Third Quarter12Tue
13Wed12:262.512:442.95:570.66:550.86:247:00Third Quarter13Wed
14Thu1:192.51:402.96:530.68:240.86:256:58Third Quarter14Thu
15Fri2:182.52:423.07:570.69:580.76:266:57Third Quarter15Fri
16Sat3:242.63:513.19:100.510:560.46:276:55Waning Crescent16Sat
17Sun4:322.94:583.310:270.311:440.26:286:53Waning Crescent17Sun
18Mon5:333.25:563.611:340.06:296:52Waning Crescent18Mon
19Tue6:263.66:493.812:28-0.112:31-0.36:306:50New Moon19Tue
20Wed7:173.97:394.01:11-0.31:25-0.56:316:48New Moon20Wed
21Thu8:074.28:294.01:53-0.52:18-0.66:326:46New Moon21Thu
22Fri8:564.39:193.92:36-0.53:10-0.56:336:45New Moon22Fri
23Sat9:464.210:093.73:18-0.54:01-0.46:346:43Waxing Crescent23Sat
24Sun9:374.110:013.43:00-0.33:56-0.25:355:41Waxing Crescent24Sun
25Mon10:323.810:563.13:44-0.15:010.15:365:40Waxing Crescent25Mon
26Tue11:303.511:562.94:350.26:160.35:375:38First Quarter26Tue
27Wed12:333.35:500.47:260.55:385:36First Quarter27Wed
28Thu12:592.71:393.07:260.68:300.65:395:35First Quarter28Thu
29Fri2:062.62:482.98:400.69:280.65:405:33First Quarter29Fri
30Sat3:142.73:512.99:420.610:160.65:415:31Waxing 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 12:59 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 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