Tides Today & Tomorrow in Boston, MA

TIDE TIMES for Tuesday, August 18, 2026
The tide is currently rising in Boston, MA.
Next low tide : 10:34 pm (0.9 ft)
Next high tide : in 5h 43m at 4:15 pm (9.9 ft)
Sunset today : 7:40 pm
Sunrise tomorrow : 5:54 am
Moon phase : First Quarter (36% illuminated)
Tide Station Location : Station #8443970
Common Questions About Tides

Boston, MA Tides - Apr 1934

DateHigh TideLow TideSunMoonDate
AMftPMftAMftPMftRiseSet
1Sun12:009.95:50-0.56:040.15:276:08Full Moon1Sun
2Mon12:1110.612:439.76:33-0.66:460.25:256:10Waning Gibbous2Mon
3Tue12:5310.71:289.57:18-0.67:300.45:236:11Waning Gibbous3Tue
4Wed1:3810.72:169.28:06-0.48:180.75:216:12Waning Gibbous4Wed
5Thu2:2810.53:118.98:59-0.19:131.05:206:13Third Quarter5Thu
6Fri3:2410.34:128.79:580.110:151.25:186:14Third Quarter6Fri
7Sat4:2710.05:188.711:010.311:201.25:166:15Third Quarter7Sat
8Sun5:359.96:258.912:050.45:156:16Third Quarter8Sun
9Mon6:449.97:309.312:271.11:090.35:136:17Waning Crescent9Mon
10Tue7:5110.08:299.81:330.72:090.15:116:19Waning Crescent10Tue
11Wed8:5210.29:2110.32:350.23:03-0.15:106:20Waning Crescent11Wed
12Thu9:4610.310:0710.73:30-0.33:52-0.25:086:21New Moon12Thu
13Fri10:3510.410:5110.94:20-0.74:38-0.25:066:22New Moon13Fri
14Sat11:2210.211:3410.95:08-0.95:220.05:056:23New Moon14Sat
15Sun12:0710.05:53-0.86:040.35:036:24New Moon15Sun
16Mon12:1510.712:519.66:37-0.66:470.75:016:25Waxing Crescent16Mon
17Tue12:5710.41:359.27:21-0.27:301.15:006:26Waxing Crescent17Tue
18Wed1:4010.12:208.88:050.38:141.54:586:27Waxing Crescent18Wed
19Thu2:259.73:088.48:520.89:021.94:576:29Waxing Crescent19Thu
20Fri3:149.33:598.29:431.29:542.24:556:30First Quarter20Fri
21Sat4:079.04:548.010:361.510:502.34:546:31First Quarter21Sat
22Sun5:048.75:488.111:301.611:462.34:526:32First Quarter22Sun
23Mon6:018.76:418.312:221.64:516:33First Quarter23Mon
24Tue6:578.77:318.712:422.11:131.54:496:34Waxing Gibbous24Tue
25Wed7:508.98:179.21:351.72:011.34:486:35Waxing Gibbous25Wed
26Thu8:399.28:599.72:261.22:461.14:466:36Waxing Gibbous26Thu
27Fri9:249.49:3810.23:120.63:280.84:456:38Waxing Gibbous27Fri
28Sat10:079.610:1810.63:570.14:100.64:436:39Full Moon28Sat
29Sun11:519.811:5911.05:41-0.45:520.45:427:40Full Moon29Sun
30Mon12:369.86:25-0.76:360.35:407:41Full Moon30Mon
DateHigh TideLow TideSunMoonDate
AMftPMftAMftPMftRiseSet
Tidal Data Source: (8443970)

Common Questions About Boston, MA Tides

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What time does the tide turn (slack tide) in Boston, MA today?

Slack tide in Boston, MA is approximately 7:24 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 Boston, MA?

Boston, MA 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 Boston, MA 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 Boston, MA?

Tide predictions for Boston, MA 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 Boston, MA?

Tide data for Boston, MA is sourced from NOAA Station #8443970. View the official NOAA station page at https://tidesandcurrents.noaa.gov/stationhome.html?id=8443970.

What is the moon phase in Boston, MA tonight?

Tonight the moon over Boston, MA is First Quarter (36% illuminated). This places Boston, MA 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