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 1h 06m 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 - Jan 2079

DateHigh TideLow TideSunMoonDate
AMftPMftAMftPMftRiseSet
1Sun9:489.710:278.43:331.54:150.47:124:22New Moon1Sun
2Mon10:289.911:078.54:141.44:540.27:124:23New Moon2Mon
3Tue11:0710.011:478.64:551.25:330.17:124:24New Moon3Tue
4Wed11:4610.15:351.16:12-0.17:124:24New Moon4Wed
5Thu12:268.612:2610.16:161.06:51-0.17:124:25Waxing Crescent5Thu
6Fri1:048.81:0710.16:580.97:31-0.27:124:26Waxing Crescent6Fri
7Sat1:448.91:4910.07:410.98:13-0.17:124:27Waxing Crescent7Sat
8Sun2:259.12:359.88:280.88:570.07:124:28Waxing Crescent8Sun
9Mon3:109.33:259.69:190.79:450.17:124:29First Quarter9Mon
10Tue3:589.54:209.310:140.610:360.37:114:31First Quarter10Tue
11Wed4:519.85:199.011:130.411:310.57:114:32First Quarter11Wed
12Thu5:4610.06:218.812:140.27:114:33Waxing Gibbous12Thu
13Fri6:4410.37:268.812:290.61:17-0.17:104:34Waxing Gibbous13Fri
14Sat7:4510.68:318.91:290.52:19-0.47:104:35Waxing Gibbous14Sat
15Sun8:4510.99:319.22:290.43:19-0.87:094:36Waxing Gibbous15Sun
16Mon9:4311.110:279.43:270.24:14-1.17:094:37Full Moon16Mon
17Tue10:3811.311:219.64:220.05:07-1.37:084:39Full Moon17Tue
18Wed11:3111.25:16-0.15:58-1.37:084:40Full Moon18Wed
19Thu12:139.712:2311.06:07-0.16:47-1.17:074:41Waning Gibbous19Thu
20Fri1:039.71:1410.66:580.07:33-0.77:074:42Waning Gibbous20Fri
21Sat1:509.62:0310.17:480.28:19-0.27:064:43Waning Gibbous21Sat
22Sun2:369.42:529.58:390.59:060.37:054:45Waning Gibbous22Sun
23Mon3:239.23:448.99:310.99:540.97:044:46Third Quarter23Mon
24Tue4:129.04:388.410:261.110:441.37:044:47Third Quarter24Tue
25Wed5:028.95:347.911:221.311:341.77:034:49Third Quarter25Wed
26Thu5:548.86:327.712:191.47:024:50Third Quarter26Thu
27Fri6:478.87:317.612:271.91:161.47:014:51Waning Crescent27Fri
28Sat7:428.98:277.71:212.02:121.27:004:52Waning Crescent28Sat
29Sun8:339.19:167.92:131.93:020.96:594:54Waning Crescent29Sun
30Mon9:209.510:008.23:021.63:470.66:584:55Waning Crescent30Mon
31Tue10:029.810:408.53:471.34:270.26:574:56New Moon31Tue
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