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 : 5:50 pm (0.5 ft)
Next high tide : in 6h 25m at 11:46 am (3.4 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 1932

DateHigh TideLow TideSunMoonDate
AMftPMftAMftPMftRiseSet
1Thu8:313.68:483.62:25-0.12:33-0.26:127:19New Moon1Thu
2Fri9:153.89:333.62:56-0.23:20-0.26:137:18Waxing Crescent2Fri
3Sat10:013.910:193.43:29-0.34:07-0.16:147:16Waxing Crescent3Sat
4Sun10:503.911:093.24:06-0.24:590.06:157:14Waxing Crescent4Sun
5Mon11:423.84:47-0.16:030.26:167:13Waxing Crescent5Mon
6Tue12:042.912:403.65:350.17:270.46:177:11First Quarter6Tue
7Wed1:032.71:443.46:350.38:490.56:187:09First Quarter7Wed
8Thu2:092.62:553.37:580.510:010.56:197:08First Quarter8Thu
9Fri3:212.64:123.29:440.511:030.56:207:06Waxing Gibbous9Fri
10Sat4:362.75:193.311:000.411:550.46:217:04Waxing Gibbous10Sat
11Sun5:382.96:123.311:590.36:227:03Waxing Gibbous11Sun
12Mon6:303.16:583.412:390.312:480.26:237:01Waxing Gibbous12Mon
13Tue7:153.37:393.41:180.21:320.26:246:59Full Moon13Tue
14Wed7:573.48:173.31:510.12:110.16:256:57Full Moon14Wed
15Thu8:363.58:533.22:190.02:450.26:266:56Full Moon15Thu
16Fri9:113.49:273.12:430.03:160.26:276:54Full Moon16Fri
17Sat9:443.310:012.93:060.13:440.36:286:52Waning Gibbous17Sat
18Sun10:153.210:362.73:320.24:140.46:296:51Waning Gibbous18Sun
19Mon10:473.011:142.54:030.44:480.66:306:49Waning Gibbous19Mon
20Tue11:232.911:572.44:380.55:290.86:316:47Waning Gibbous20Tue
21Wed12:062.75:180.76:260.96:326:45Third Quarter21Wed
22Thu12:462.212:582.66:070.88:321.06:336:44Third Quarter22Thu
23Fri1:422.11:592.67:080.99:501.06:346:42Third Quarter23Fri
24Sat2:462.23:102.78:210.910:450.86:356:40Third Quarter24Sat
25Sun2:582.33:242.88:450.710:280.65:365:39Waning Crescent25Sun
26Mon4:002.64:213.19:580.511:040.45:375:37Waning Crescent26Mon
27Tue4:503.05:093.310:520.211:360.15:385:35Waning Crescent27Tue
28Wed5:353.45:543.511:420.05:395:34New Moon28Wed
29Thu6:203.76:393.612:08-0.112:30-0.25:405:32New Moon29Thu
30Fri7:044.07:243.612:42-0.31:19-0.45:415:30New Moon30Fri
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 2:48 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 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