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 4h 05m 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 - Mar 1931

DateHigh TideLow TideSunMoonDate
AMftPMftAMftPMftRiseSet
1Sun4:413.05:112.611:32-0.211:05-0.46:215:36Waxing Gibbous1Sun
2Mon5:363.36:023.012:15-0.56:205:37Waxing Gibbous2Mon
3Tue6:273.56:523.412:03-0.612:57-0.76:185:38Full Moon3Tue
4Wed7:153.67:403.612:57-0.81:36-0.86:175:39Full Moon4Wed
5Thu8:023.68:273.81:49-0.92:13-0.96:155:40Full Moon5Thu
6Fri8:493.49:153.82:39-0.92:49-0.86:135:41Waning Gibbous6Fri
7Sat9:363.110:043.63:28-0.73:24-0.66:125:42Waning Gibbous7Sat
8Sun10:252.810:563.44:21-0.44:02-0.46:105:44Waning Gibbous8Sun
9Mon11:182.511:533.05:26-0.14:45-0.16:095:45Third Quarter9Mon
10Tue12:162.26:420.25:390.26:075:46Third Quarter10Tue
11Wed12:562.71:202.07:580.47:060.46:055:47Third Quarter11Wed
12Thu2:102.52:361.99:100.49:010.56:045:48Third Quarter12Thu
13Fri3:292.43:512.010:100.410:110.46:025:49Waning Crescent13Fri
14Sat4:322.54:482.210:590.311:030.36:005:50Waning Crescent14Sat
15Sun5:212.65:342.411:390.211:450.25:595:51Waning Crescent15Sun
16Mon6:012.76:142.612:130.15:575:53Waning Crescent16Mon
17Tue6:372.86:492.812:220.012:43-0.15:555:54New Moon17Tue
18Wed7:082.87:212.912:57-0.11:09-0.25:545:55New Moon18Wed
19Thu7:382.87:513.01:30-0.11:32-0.25:525:56New Moon19Thu
20Fri8:082.78:193.02:00-0.11:55-0.25:505:57New Moon20Fri
21Sat8:382.78:493.02:29-0.12:19-0.25:495:58Waxing Crescent21Sat
22Sun9:112.59:222.92:570.02:48-0.15:475:59Waxing Crescent22Sun
23Mon9:482.410:002.93:280.13:200.05:456:00Waxing Crescent23Mon
24Tue10:312.210:442.84:040.23:590.15:446:01Waxing Crescent24Tue
25Wed11:212.111:372.74:500.44:460.25:426:02First Quarter25Wed
26Thu12:182.15:520.55:440.35:406:03First Quarter26Thu
27Fri12:392.61:242.17:400.56:560.35:386:04First Quarter27Fri
28Sat1:502.72:382.29:150.48:220.25:376:06First Quarter28Sat
29Sun3:082.83:502.510:130.19:520.05:356:07Waxing Gibbous29Sun
30Mon4:183.04:502.911:00-0.110:58-0.35:336:08Waxing Gibbous30Mon
31Tue5:143.35:423.411:42-0.411:55-0.55:326:09Waxing Gibbous31Tue
DateHigh TideLow TideSunMoonDate
AMftPMftAMftPMftRiseSet
Tidal Data Source: (8459338)

Common Questions About Block Island, RI Tides

Show All
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