Tides Today & Tomorrow in Block Island, RI

TIDE TIMES for Tuesday, August 18, 2026
The tide is currently rising in Block Island, RI.
Next low tide (tomorrow) : 6:05 am (0.6 ft)
Next high tide (tomorrow) : in 2h 09m at 12:45 am (2.5 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 - Aug 1929

DateHigh TideLow TideSunMoonDate
AMftPMftAMftPMftRiseSet
1Thu4:292.75:023.610:050.15:418:03Waning Crescent1Thu
2Fri5:362.86:053.812:000.211:15 AM0.05:428:02Waning Crescent2Fri
3Sat6:353.17:024.012:550.012:20-0.25:438:01New Moon3Sat
4Sun7:303.37:564.11:47-0.21:21-0.35:448:00New Moon4Sun
5Mon8:233.58:474.12:36-0.32:19-0.45:457:59New Moon5Mon
6Tue9:133.69:363.93:21-0.33:12-0.35:467:57New Moon6Tue
7Wed10:033.610:243.74:03-0.34:03-0.25:477:56Waxing Crescent7Wed
8Thu10:533.611:113.44:43-0.24:540.05:487:55Waxing Crescent8Thu
9Fri11:433.511:593.05:200.05:510.35:497:54Waxing Crescent9Fri
10Sat12:353.35:560.26:550.55:507:52First Quarter10Sat
11Sun12:482.71:263.16:320.48:010.75:517:51First Quarter11Sun
12Mon1:382.52:203.07:120.69:060.85:527:50First Quarter12Mon
13Tue2:332.33:202.88:000.710:090.85:537:48First Quarter13Tue
14Wed3:382.24:272.89:000.811:060.85:547:47Waxing Gibbous14Wed
15Thu4:482.25:272.810:180.811:550.75:557:46Waxing Gibbous15Thu
16Fri5:452.36:162.911:220.75:567:44Waxing Gibbous16Fri
17Sat6:302.46:583.012:390.612:110.65:577:43Waxing Gibbous17Sat
18Sun7:092.67:343.21:200.512:560.45:587:41Full Moon18Sun
19Mon7:462.88:083.31:580.41:370.35:597:40Full Moon19Mon
20Tue8:212.98:413.32:310.22:160.36:007:38Full Moon20Tue
21Wed8:573.09:143.32:590.22:520.26:017:37Full Moon21Wed
22Thu9:333.19:503.23:240.13:280.36:027:35Waning Gibbous22Thu
23Fri10:123.210:293.13:490.14:050.36:037:34Waning Gibbous23Fri
24Sat10:533.311:123.04:180.14:460.46:047:32Waning Gibbous24Sat
25Sun11:383.34:540.15:350.56:057:31Waning Gibbous25Sun
26Mon12:012.812:283.35:360.26:370.66:067:29Third Quarter26Mon
27Tue12:562.71:243.36:280.38:040.66:077:28Third Quarter27Tue
28Wed1:562.62:263.37:290.39:400.66:087:26Third Quarter28Wed
29Thu3:032.63:383.38:390.310:520.46:097:25Waning Crescent29Thu
30Fri4:172.74:523.510:020.311:500.26:107:23Waning Crescent30Fri
31Sat5:252.95:563.611:200.16:117:21Waning Crescent31Sat
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 3:25 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