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 5h 28m 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 - Jan 1923

DateHigh TideLow TideSunMoonDate
AMftPMftAMftPMftRiseSet
1Mon5:563.16:212.612:42-0.27:114:27Full Moon1Mon
2Tue6:373.37:032.812:01-0.31:20-0.37:124:28Full Moon2Tue
3Wed7:193.47:462.912:43-0.41:55-0.47:124:29Full Moon3Wed
4Thu8:023.48:313.01:26-0.52:29-0.47:124:30Full Moon4Thu
5Fri8:473.49:183.02:11-0.53:04-0.47:124:31Waning Gibbous5Fri
6Sat9:343.310:083.02:57-0.43:43-0.47:124:32Waning Gibbous6Sat
7Sun10:253.111:033.03:46-0.34:27-0.37:124:32Waning Gibbous7Sun
8Mon11:192.94:44-0.15:21-0.27:114:33Third Quarter8Mon
9Tue12:003.012:172.86:010.06:24-0.27:114:34Third Quarter9Tue
10Wed1:013.01:192.67:370.17:35-0.17:114:36Third Quarter10Wed
11Thu2:063.02:272.58:570.08:49-0.17:114:37Third Quarter11Thu
12Fri3:153.13:382.510:04-0.19:56-0.27:114:38Waning Crescent12Fri
13Sat4:193.24:412.611:01-0.210:52-0.37:104:39Waning Crescent13Sat
14Sun5:163.35:362.711:52-0.311:43-0.47:104:40Waning Crescent14Sun
15Mon6:063.46:262.812:39-0.47:094:41New Moon15Mon
16Tue6:533.47:122.912:30-0.41:22-0.57:094:42New Moon16Tue
17Wed7:383.47:562.91:13-0.42:01-0.57:094:43New Moon17Wed
18Thu8:193.38:382.91:51-0.42:34-0.47:084:44New Moon18Thu
19Fri8:583.19:192.82:24-0.33:04-0.37:084:45Waxing Crescent19Fri
20Sat9:362.99:582.62:56-0.13:30-0.27:074:47Waxing Crescent20Sat
21Sun10:142.710:382.53:290.03:58-0.17:064:48Waxing Crescent21Sun
22Mon10:532.411:192.44:080.24:320.07:064:49Waxing Crescent22Mon
23Tue11:352.24:540.45:130.27:054:50First Quarter23Tue
24Wed12:012.312:202.15:530.56:000.37:044:51First Quarter24Wed
25Thu12:462.21:101.97:260.66:530.37:044:53First Quarter25Thu
26Fri1:382.22:101.98:590.57:520.37:034:54First Quarter26Fri
27Sat2:412.33:201.910:010.48:580.27:024:55Waxing Gibbous27Sat
28Sun3:482.54:212.110:520.210:010.07:014:56Waxing Gibbous28Sun
29Mon4:432.75:102.311:360.010:55-0.27:004:58Waxing Gibbous29Mon
30Tue5:303.05:562.612:17-0.27:004:59Waxing Gibbous30Tue
31Wed6:153.26:412.912:57-0.46:595:00Full Moon31Wed
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