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 52m 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 - Nov 1929

DateHigh TideLow TideSunMoonDate
AMftPMftAMftPMftRiseSet
1Fri7:053.87:223.112:35-0.11:26-0.16:174:42New Moon1Fri
2Sat7:453.78:022.91:03-0.12:010.06:184:41New Moon2Sat
3Sun8:223.58:412.81:310.02:320.16:194:40Waxing Crescent3Sun
4Mon8:593.39:202.62:030.23:040.36:204:39Waxing Crescent4Mon
5Tue9:373.010:012.42:370.33:380.46:224:37Waxing Crescent5Tue
6Wed10:192.810:482.33:150.54:220.66:234:36Waxing Crescent6Wed
7Thu11:062.611:402.13:580.75:330.86:244:35First Quarter7Thu
8Fri12:012.54:510.87:080.86:254:34First Quarter8Fri
9Sat12:372.112:592.46:000.98:100.86:264:33First Quarter9Sat
10Sun1:372.22:012.47:460.98:590.66:284:32First Quarter10Sun
11Mon2:402.33:032.59:100.89:380.56:294:31Waxing Gibbous11Mon
12Tue3:352.63:562.610:050.510:110.36:304:30Waxing Gibbous12Tue
13Wed4:212.94:422.810:510.310:420.16:314:29Waxing Gibbous13Wed
14Thu5:023.25:252.911:340.111:15-0.16:324:28Waxing Gibbous14Thu
15Fri5:433.66:083.012:16-0.16:344:27Full Moon15Fri
16Sat6:263.86:533.11:00-0.36:354:27Full Moon16Sat
17Sun7:114.07:403.112:32-0.41:44-0.36:364:26Full Moon17Sun
18Mon7:594.08:293.11:16-0.42:30-0.36:374:25Waning Gibbous18Mon
19Tue8:493.99:213.02:02-0.43:20-0.26:384:24Waning Gibbous19Tue
20Wed9:423.710:162.92:51-0.34:180.06:394:24Waning Gibbous20Wed
21Thu10:413.511:182.83:45-0.15:330.16:414:23Waning Gibbous21Thu
22Fri11:443.24:510.16:470.26:424:22Third Quarter22Fri
23Sat12:222.812:493.06:300.37:500.26:434:22Third Quarter23Sat
24Sun1:292.91:562.98:010.38:460.16:444:21Third Quarter24Sun
25Mon2:353.03:022.79:130.29:360.16:454:21Waning Crescent25Mon
26Tue3:383.14:022.710:140.210:200.06:464:20Waning Crescent26Tue
27Wed4:333.34:532.711:050.110:580.06:474:20Waning Crescent27Wed
28Thu5:213.45:382.711:500.011:320.06:494:19Waning Crescent28Thu
29Fri6:043.56:212.712:310.06:504:19New Moon29Fri
30Sat6:443.47:012.712:020.01:090.06:514:18New Moon30Sat
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 9:47 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