Tides Today & Tomorrow in Boston, MA

TIDE TIMES for Friday, August 21, 2026
The tide is currently rising in Boston, MA.
Next low tide : 12:34 pm (2.3 ft)
Next high tide : in 2h 16m at 6:40 am (8.0 ft)
Sunset today : 7:36 pm
Sunrise tomorrow : 5:57 am
Moon phase : First Quarter (65% illuminated)
Tide Station Location : Station #8443970
Common Questions About Tides

Boston, MA Tides - Oct 1926

DateHigh TideLow TideSunMoonDate
AMftPMftAMftPMftRiseSet
1Fri7:118.67:259.412:511.11:031.95:405:27Waning Crescent1Fri
2Sat8:078.88:199.51:481.12:001.75:415:25Waning Crescent2Sat
3Sun8:549.19:069.62:381.02:501.45:425:23Waning Crescent3Sun
4Mon9:359.39:489.83:210.93:341.15:435:21Waning Crescent4Mon
5Tue10:129.610:279.93:590.74:140.85:445:20New Moon5Tue
6Wed10:479.811:049.94:350.64:520.65:455:18New Moon6Wed
7Thu11:2110.011:429.85:100.65:300.45:475:16New Moon7Thu
8Fri11:5610.15:470.66:090.35:485:15New Moon8Fri
9Sat12:209.712:3210.16:230.76:480.35:495:13Waxing Crescent9Sat
10Sun12:589.51:0910.17:010.97:290.45:505:11Waxing Crescent10Sun
11Mon1:399.31:4810.17:421.18:130.55:515:10Waxing Crescent11Mon
12Tue2:239.12:3210.08:251.39:010.65:525:08Waxing Crescent12Tue
13Wed3:128.83:2310.09:151.59:550.75:535:06First Quarter13Wed
14Thu4:078.74:209.910:111.610:530.65:545:05First Quarter14Thu
15Fri5:068.85:2110.011:111.511:530.55:565:03First Quarter15Fri
16Sat6:089.16:2510.212:141.25:575:01Waxing Gibbous16Sat
17Sun7:099.57:2810.512:530.21:160.75:585:00Waxing Gibbous17Sun
18Mon8:0810.18:2910.91:52-0.22:170.15:594:58Waxing Gibbous18Mon
19Tue9:0310.89:2611.22:48-0.63:14-0.66:004:57Full Moon19Tue
20Wed9:5311.310:2011.33:40-0.94:08-1.16:024:55Full Moon20Wed
21Thu10:4311.711:1211.24:30-1.05:00-1.46:034:54Full Moon21Thu
22Fri11:3111.85:19-0.95:51-1.56:044:52Full Moon22Fri
23Sat12:0511.012:2011.76:08-0.66:41-1.36:054:51Waning Gibbous23Sat
24Sun12:5610.61:0911.36:57-0.17:32-0.96:064:49Waning Gibbous24Sun
25Mon1:4810.11:5910.87:460.48:24-0.36:084:48Waning Gibbous25Mon
26Tue2:429.52:5210.38:381.09:180.36:094:46Third Quarter26Tue
27Wed3:389.13:489.79:331.610:160.86:104:45Third Quarter27Wed
28Thu4:378.74:479.310:311.911:141.16:114:43Third Quarter28Thu
29Fri5:368.65:479.111:302.16:124:42Third Quarter29Fri
30Sat6:338.66:469.012:111.312:292.06:144:41Waning Crescent30Sat
31Sun7:268.87:419.11:051.31:251.86:154:39Waning Crescent31Sun
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 9:37 am — 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 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 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 (65% 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