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 5h 56m at 6:49 pm (0.7 ft)
Next high tide (tomorrow) : 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 - Feb 1930

DateHigh TideLow TideSunMoonDate
AMftPMftAMftPMftRiseSet
1Sat9:012.89:202.52:32-0.13:06-0.26:575:02Waxing Crescent1Sat
2Sun9:352.69:562.63:050.03:30-0.16:565:03Waxing Crescent2Sun
3Mon10:122.510:362.63:420.14:01-0.16:555:04Waxing Crescent3Mon
4Tue10:542.311:212.64:240.24:37-0.16:545:05Waxing Crescent4Tue
5Wed11:432.25:160.35:220.06:535:07First Quarter5Wed
6Thu12:112.612:382.16:210.46:160.06:525:08First Quarter6Thu
7Fri1:072.71:422.07:510.37:190.06:515:09First Quarter7Fri
8Sat2:142.72:562.19:330.28:310.06:505:10Waxing Gibbous8Sat
9Sun3:292.94:082.310:380.09:49-0.26:495:12Waxing Gibbous9Sun
10Mon4:383.25:102.611:32-0.310:59-0.46:475:13Waxing Gibbous10Mon
11Tue5:373.46:042.912:22-0.56:465:14Waxing Gibbous11Tue
12Wed6:313.66:563.21:09-0.76:455:15Full Moon12Wed
13Thu7:213.77:463.412:56-0.81:53-0.86:445:17Full Moon13Thu
14Fri8:093.78:343.51:48-0.92:32-0.86:425:18Full Moon14Fri
15Sat8:563.59:223.52:38-0.83:09-0.76:415:19Waning Gibbous15Sat
16Sun9:423.210:103.33:27-0.63:44-0.66:405:20Waning Gibbous16Sun
17Mon10:292.811:013.14:17-0.44:17-0.46:385:22Waning Gibbous17Mon
18Tue11:182.511:532.95:16-0.14:52-0.16:375:23Third Quarter18Tue
19Wed12:102.16:260.25:330.16:365:24Third Quarter19Wed
20Thu12:492.61:071.97:400.46:250.46:345:25Third Quarter20Thu
21Fri1:532.42:161.88:520.57:410.56:335:26Third Quarter21Fri
22Sat3:102.33:351.89:560.59:330.56:315:28Waning Crescent22Sat
23Sun4:192.34:371.910:490.410:350.46:305:29Waning Crescent23Sun
24Mon5:122.45:252.111:330.311:220.26:285:30Waning Crescent24Mon
25Tue5:542.66:052.312:120.16:275:31Waning Crescent25Tue
26Wed6:312.76:412.512:030.112:470.06:255:32New Moon26Wed
27Thu7:032.87:142.612:41-0.11:18-0.16:245:34New Moon27Thu
28Fri7:332.97:452.81:16-0.21:45-0.26:225:35New Moon28Fri
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 9:47 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 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