Tides Today & Tomorrow in Block Island, RI

TIDE TIMES for Tuesday, August 18, 2026
The tide is currently falling in Block Island, RI.
Next low tide : in 3h 19m at 5:28 am (0.4 ft)
Next high tide : 12:33 pm (3.1 ft)
Sunset today : 7:41 pm
Sunrise tomorrow : 5:59 am
Moon phase : First Quarter (36% illuminated)
Tide Station Location : Station #8459338
Common Questions About Tides

Block Island, RI Tides - Feb 1931

DateHigh TideLow TideSunMoonDate
AMftPMftAMftPMftRiseSet
1Sun5:543.36:202.712:41-0.46:585:01Full Moon1Sun
2Mon6:443.67:103.012:09-0.61:24-0.66:575:03Full Moon2Mon
3Tue7:333.77:593.21:03-0.82:05-0.76:565:04Full Moon3Tue
4Wed8:213.68:473.41:55-0.92:43-0.86:555:05Waning Gibbous4Wed
5Thu9:083.59:373.42:46-0.83:21-0.86:535:06Waning Gibbous5Thu
6Fri9:573.210:293.43:38-0.73:59-0.66:525:08Waning Gibbous6Fri
7Sat10:482.911:233.34:37-0.44:39-0.46:515:09Waning Gibbous7Sat
8Sun11:422.55:49-0.15:26-0.26:505:10Third Quarter8Sun
9Mon12:203.112:402.27:080.16:210.06:495:11Third Quarter9Mon
10Tue1:232.91:442.08:250.27:370.26:485:13Third Quarter10Tue
11Wed2:342.73:001.99:360.39:120.36:475:14Waning Crescent11Wed
12Thu3:492.64:112.010:360.310:230.26:455:15Waning Crescent12Thu
13Fri4:512.75:082.111:260.211:170.16:445:16Waning Crescent13Fri
14Sat5:422.75:552.312:090.16:435:18Waning Crescent14Sat
15Sun6:252.86:372.512:020.012:460.06:415:19New Moon15Sun
16Mon7:032.97:162.612:41-0.11:19-0.16:405:20New Moon16Mon
17Tue7:372.97:512.71:15-0.11:48-0.26:395:21New Moon17Tue
18Wed8:082.98:232.71:47-0.22:13-0.36:375:23New Moon18Wed
19Thu8:382.88:532.72:16-0.22:35-0.36:365:24Waxing Crescent19Thu
20Fri9:072.79:242.72:46-0.12:57-0.26:355:25Waxing Crescent20Fri
21Sat9:392.59:562.63:160.03:23-0.16:335:26Waxing Crescent21Sat
22Sun10:152.310:322.63:500.13:540.06:325:27Waxing Crescent22Sun
23Mon10:562.111:142.54:300.34:310.16:305:29Waxing Crescent23Mon
24Tue11:432.05:180.45:160.26:295:30First Quarter24Tue
25Wed12:042.512:391.96:220.56:120.26:275:31First Quarter25Wed
26Thu1:022.51:441.98:120.57:180.36:265:32First Quarter26Thu
27Fri2:132.53:002.09:470.48:360.16:245:33Waxing Gibbous27Fri
28Sat3:332.74:122.310:440.19:59-0.16:235:34Waxing Gibbous28Sat
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 9:00 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 36% 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 (36% 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