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 4h 01m at 7:49 am (0.9 ft)
Next high tide : 3:23 pm (2.6 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 - Mar 1924

DateHigh TideLow TideSunMoonDate
AMftPMftAMftPMftRiseSet
1Sat4:003.04:252.610:43-0.110:47-0.26:205:36Waning Crescent1Sat
2Sun5:003.15:222.811:34-0.311:41-0.36:195:38Waning Crescent2Sun
3Mon5:523.26:123.012:20-0.46:175:39Waning Crescent3Mon
4Tue6:393.36:583.212:30-0.41:00-0.56:155:40New Moon4Tue
5Wed7:223.37:403.21:14-0.51:36-0.56:145:41New Moon5Wed
6Thu8:033.28:213.21:53-0.42:06-0.56:125:42New Moon6Thu
7Fri8:413.18:583.12:27-0.42:31-0.46:115:43Waxing Crescent7Fri
8Sat9:182.99:342.92:56-0.22:55-0.36:095:44Waxing Crescent8Sat
9Sun9:552.610:102.83:25-0.13:23-0.16:075:46Waxing Crescent9Sun
10Mon10:332.410:462.63:570.13:560.06:065:47Waxing Crescent10Mon
11Tue11:152.211:262.44:370.34:360.26:045:48First Quarter11Tue
12Wed12:002.05:280.55:230.46:025:49First Quarter12Wed
13Thu12:122.312:521.96:510.66:190.56:015:50First Quarter13Thu
14Fri1:052.21:531.98:420.67:250.55:595:51First Quarter14Fri
15Sat2:122.23:062.09:460.58:460.45:575:52First Quarter15Sat
16Sun3:302.44:102.210:350.310:040.25:565:53Waxing Gibbous16Sun
17Mon4:312.64:592.511:170.110:580.05:545:54Waxing Gibbous17Mon
18Tue5:172.85:422.811:53-0.111:45-0.25:525:55Waxing Gibbous18Tue
19Wed6:003.16:243.112:27-0.35:515:57Full Moon19Wed
20Thu6:433.37:073.412:31-0.51:00-0.55:495:58Full Moon20Thu
21Fri7:273.47:523.61:15-0.61:33-0.65:475:59Full Moon21Fri
22Sat8:123.48:373.72:00-0.72:08-0.75:466:00Full Moon22Sat
23Sun8:583.39:253.72:44-0.72:46-0.65:446:01Waning Gibbous23Sun
24Mon9:473.110:153.63:31-0.53:28-0.55:426:02Waning Gibbous24Mon
25Tue10:402.911:113.44:25-0.34:15-0.35:416:03Waning Gibbous25Tue
26Wed11:382.75:37-0.15:12-0.15:396:04Third Quarter26Wed
27Thu12:123.212:402.67:030.06:300.15:376:05Third Quarter27Thu
28Fri1:183.01:492.58:190.18:190.25:366:06Third Quarter28Fri
29Sat2:312.93:032.69:250.19:390.15:346:07Waning Crescent29Sat
30Sun3:432.94:102.710:220.010:400.05:326:08Waning Crescent30Sun
31Mon4:442.95:062.911:11-0.111:32-0.15:316:09Waning Crescent31Mon
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 11:36 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