Tides Today & Tomorrow in Block Island, RI

TIDE TIMES for Tuesday, August 18, 2026
The tide is currently rising in Block Island, RI.
Next low tide : 6:49 pm (0.7 ft)
Next high tide : in 2h 46m at 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 - Jun 1930

DateHigh TideLow TideSunMoonDate
AMftPMftAMftPMftRiseSet
1Sun11:483.05:540.05:210.15:158:12Waxing Crescent1Sun
2Mon12:093.412:483.06:590.16:370.25:158:12First Quarter2Mon
3Tue1:093.21:493.08:000.18:080.35:148:13First Quarter3Tue
4Wed2:093.02:513.18:550.19:270.35:148:14First Quarter4Wed
5Thu3:112.83:553.39:460.110:350.35:148:14First Quarter5Thu
6Fri4:152.74:563.410:350.111:350.25:138:15Waxing Gibbous6Fri
7Sat5:162.65:503.511:190.15:138:16Waxing Gibbous7Sat
8Sun6:092.76:393.612:270.212:000.15:138:16Waxing Gibbous8Sun
9Mon6:582.77:243.61:150.212:390.15:138:17Full Moon9Mon
10Tue7:442.78:083.51:590.11:170.25:138:17Full Moon10Tue
11Wed8:292.78:503.42:390.11:560.25:128:18Full Moon11Wed
12Thu9:112.79:313.33:170.22:350.35:128:19Full Moon12Thu
13Fri9:532.710:103.13:530.23:140.45:128:19Waning Gibbous13Fri
14Sat10:352.610:503.04:290.33:530.55:128:19Waning Gibbous14Sat
15Sun11:172.511:302.85:070.44:340.65:128:20Waning Gibbous15Sun
16Mon12:022.45:490.55:200.75:128:20Waning Gibbous16Mon
17Tue12:122.712:462.46:340.56:160.85:128:21Third Quarter17Tue
18Wed12:542.61:302.57:150.67:230.95:128:21Third Quarter18Wed
19Thu1:392.52:152.67:540.68:400.85:128:21Third Quarter19Thu
20Fri2:282.43:042.78:340.59:540.75:138:22Third Quarter20Fri
21Sat3:242.43:582.99:190.410:560.65:138:22Waning Crescent21Sat
22Sun4:262.44:543.210:090.311:490.45:138:22Waning Crescent22Sun
23Mon5:252.55:473.411:000.25:138:22Waning Crescent23Mon
24Tue6:182.76:383.712:390.211:51 AM0.05:148:22Waning Crescent24Tue
25Wed7:102.87:293.91:280.012:43-0.15:148:23New Moon25Wed
26Thu8:013.08:214.02:18-0.11:36-0.25:148:23New Moon26Thu
27Fri8:523.19:134.03:07-0.22:31-0.35:158:23New Moon27Fri
28Sat9:443.210:063.93:55-0.23:25-0.35:158:23Waxing Crescent28Sat
29Sun10:383.310:593.84:43-0.24:21-0.25:158:23Waxing Crescent29Sun
30Mon11:333.311:533.55:35-0.15:230.05:168:23Waxing Crescent30Mon
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 3:41 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