Tides Today & Tomorrow in Block Island, RI

TIDE TIMES for Friday, August 21, 2026
The tide is currently rising in Block Island, RI.
Next low tide : 10:17 pm (0.9 ft)
Next high tide : in 3h 15m at 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 - Jul 1923

DateHigh TideLow TideSunMoonDate
AMftPMftAMftPMftRiseSet
1Sun10:323.210:543.54:31-0.14:190.15:168:23Waning Gibbous1Sun
2Mon11:213.111:413.25:120.05:040.35:178:22Waning Gibbous2Mon
3Tue12:113.05:530.25:570.55:178:22Waning Gibbous3Tue
4Wed12:282.91:002.86:340.37:060.75:188:22Third Quarter4Wed
5Thu1:142.71:482.77:140.58:140.85:188:22Third Quarter5Thu
6Fri2:012.52:372.77:530.59:180.85:198:22Third Quarter6Fri
7Sat2:512.43:302.78:360.610:180.85:198:21Third Quarter7Sat
8Sun3:492.34:272.89:250.611:120.75:208:21Waning Crescent8Sun
9Mon4:502.35:182.910:180.55:218:21Waning Crescent9Mon
10Tue5:412.46:023.012:000.611:09 AM0.45:218:20Waning Crescent10Tue
11Wed6:252.56:423.212:450.411:56 AM0.35:228:20Waning Crescent11Wed
12Thu7:072.77:223.41:290.312:410.25:238:19New Moon12Thu
13Fri7:482.98:023.52:090.21:250.15:248:19New Moon13Fri
14Sat8:313.08:443.62:470.12:100.05:248:18New Moon14Sat
15Sun9:143.19:273.63:200.02:540.05:258:18New Moon15Sun
16Mon9:593.210:123.53:520.03:390.05:268:17Waxing Crescent16Mon
17Tue10:463.311:003.44:250.04:260.15:278:17Waxing Crescent17Tue
18Wed11:373.311:513.35:030.05:180.25:288:16Waxing Crescent18Wed
19Thu12:313.45:490.06:220.35:288:15First Quarter19Thu
20Fri12:453.11:273.46:410.17:420.45:298:15First Quarter20Fri
21Sat1:423.02:263.47:400.19:080.45:308:14First Quarter21Sat
22Sun2:442.93:303.58:450.110:220.35:318:13First Quarter22Sun
23Mon3:522.84:383.59:580.111:250.25:328:12Waxing Gibbous23Mon
24Tue5:012.95:403.711:070.15:338:11Waxing Gibbous24Tue
25Wed6:033.06:363.812:210.112:070.05:348:11Waxing Gibbous25Wed
26Thu6:573.27:273.81:120.01:01-0.15:358:10Full Moon26Thu
27Fri7:483.38:153.82:00-0.11:52-0.15:368:09Full Moon27Fri
28Sat8:373.39:013.72:44-0.12:38-0.15:368:08Full Moon28Sat
29Sun9:223.39:443.63:23-0.13:190.05:378:07Full Moon29Sun
30Mon10:063.310:253.43:57-0.13:570.25:388:06Waning Gibbous30Mon
31Tue10:493.211:063.14:280.14:320.35:398:05Waning Gibbous31Tue
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 6:50 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 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