Tides Today & Tomorrow in Boston, MA

TIDE TIMES for Tuesday, July 21, 2026
The tide is currently rising in Boston, MA.
Next low tide (tomorrow) : 12:07 am (1.1 ft)
Next high tide : in 3h 40m at 5:48 pm (9.7 ft)
Sunset today : 8:14 pm
Sunrise tomorrow : 5:26 am
Moon phase : First Quarter (52% illuminated)
Tide Station Location : Station #8443970
Common Questions About Tides

Boston, MA Tides - Dec 2078

DateHigh TideLow TideSunMoonDate
AMftPMftAMftPMftRiseSet
1Thu9:019.79:328.82:441.33:200.76:534:12Waning Crescent1Thu
2Fri9:399.810:128.83:251.34:010.56:544:12New Moon2Fri
3Sat10:169.910:528.84:041.34:390.46:554:11New Moon3Sat
4Sun10:5310.011:318.74:421.45:180.36:564:11New Moon4Sun
5Mon11:3010.05:201.45:560.36:574:11New Moon5Mon
6Tue12:108.612:099.96:001.56:360.36:584:11Waxing Crescent6Tue
7Wed12:508.512:499.86:401.67:160.46:594:11Waxing Crescent7Wed
8Thu1:318.41:309.77:211.77:580.57:004:11Waxing Crescent8Thu
9Fri2:138.42:149.68:061.78:420.57:014:11Waxing Crescent9Fri
10Sat2:588.43:029.58:541.79:300.67:024:11First Quarter10Sat
11Sun3:468.63:549.49:471.610:210.67:034:11First Quarter11Sun
12Mon4:378.94:519.310:441.411:130.57:034:11First Quarter12Mon
13Tue5:299.35:499.311:421.07:044:11First Quarter13Tue
14Wed6:229.96:499.412:060.412:420.47:054:12Waxing Gibbous14Wed
15Thu7:1610.47:509.61:010.31:41-0.27:064:12Waxing Gibbous15Thu
16Fri8:1111.08:489.81:570.12:39-0.87:064:12Waxing Gibbous16Fri
17Sat9:0411.59:449.92:51-0.23:34-1.37:074:12Full Moon17Sat
18Sun9:5711.810:3810.03:45-0.34:28-1.67:084:13Full Moon18Sun
19Mon10:4911.911:3310.04:37-0.45:20-1.77:084:13Full Moon19Mon
20Tue11:4311.85:30-0.46:13-1.67:094:14Waning Gibbous20Tue
21Wed12:289.912:3711.56:23-0.27:05-1.37:094:14Waning Gibbous21Wed
22Thu1:219.71:3111.07:160.17:57-0.97:104:15Waning Gibbous22Thu
23Fri2:159.52:2510.48:100.58:49-0.37:104:15Waning Gibbous23Fri
24Sat3:099.33:219.89:060.99:430.27:114:16Third Quarter24Sat
25Sun4:049.14:209.210:051.210:370.77:114:16Third Quarter25Sun
26Mon4:599.05:198.711:051.411:301.17:114:17Third Quarter26Mon
27Tue5:528.96:188.412:041.47:124:18Third Quarter27Tue
28Wed6:459.07:168.212:221.41:031.47:124:18Waning Crescent28Wed
29Thu7:359.18:128.11:141.61:581.27:124:19Waning Crescent29Thu
30Fri8:239.39:018.22:041.72:490.97:124:20Waning Crescent30Fri
31Sat9:079.59:468.32:501.63:340.77:124:21Waning Crescent31Sat
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 8:57 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 neap phase. Tonight's moon is 52% 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 near their weekly minimum.

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 (52% illuminated). This places Boston, MA in a neap tide cycle, so tidal ranges are near their weekly minimum 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