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 1h 23m 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 - Oct 1933

DateHigh TideLow TideSunMoonDate
AMftPMftAMftPMftRiseSet
1Sun9:039.99:2210.42:440.23:050.45:405:26Waxing Gibbous1Sun
2Mon9:5110.310:1210.43:350.03:570.05:415:24Full Moon2Mon
3Tue10:3410.510:5910.34:200.04:44-0.25:425:23Full Moon3Tue
4Wed11:1510.611:4310.15:030.25:29-0.35:445:21Full Moon4Wed
5Thu11:5510.55:440.46:13-0.15:455:19Waning Gibbous5Thu
6Fri12:269.812:3510.46:240.86:550.15:465:17Waning Gibbous6Fri
7Sat1:099.41:1510.17:051.27:380.55:475:16Waning Gibbous7Sat
8Sun1:529.01:579.87:471.68:230.95:485:14Waning Gibbous8Sun
9Mon2:388.52:439.48:322.09:121.35:495:12Third Quarter9Mon
10Tue3:278.23:349.19:212.310:051.65:505:11Third Quarter10Tue
11Wed4:228.04:298.910:152.511:001.75:515:09Third Quarter11Wed
12Thu5:187.95:278.911:112.611:541.75:535:07Third Quarter12Thu
13Fri6:138.16:238.912:072.45:545:06Third Quarter13Fri
14Sat7:058.47:179.112:471.61:022.15:555:04Waning Crescent14Sat
15Sun7:538.98:089.41:361.31:541.55:565:03Waning Crescent15Sun
16Mon8:379.58:559.82:220.92:430.95:575:01Waning Crescent16Mon
17Tue9:1710.19:3910.13:060.63:290.35:584:59New Moon17Tue
18Wed9:5710.610:2310.23:470.34:14-0.36:004:58New Moon18Wed
19Thu10:3711.111:0810.34:290.04:59-0.86:014:56New Moon19Thu
20Fri11:2011.411:5510.25:12-0.15:45-1.06:024:55New Moon20Fri
21Sat12:0611.65:580.06:34-1.16:034:53Waxing Crescent21Sat
22Sun12:4410.112:5511.56:450.17:24-0.96:044:52Waxing Crescent22Sun
23Mon1:369.81:4711.37:360.48:18-0.66:054:50Waxing Crescent23Mon
24Tue2:329.42:4410.88:320.89:17-0.16:074:49First Quarter24Tue
25Wed3:349.13:4810.49:331.110:200.26:084:47First Quarter25Wed
26Thu4:409.04:5610.010:391.311:240.46:094:46First Quarter26Thu
27Fri5:479.16:049.811:461.36:104:44Waxing Gibbous27Fri
28Sat6:519.47:129.712:270.612:531.16:124:43Waxing Gibbous28Sat
29Sun7:519.78:149.81:270.61:560.86:134:42Waxing Gibbous29Sun
30Mon8:4310.19:089.82:220.52:530.46:144:40Waxing Gibbous30Mon
31Tue9:2910.39:569.73:110.63:420.16:154:39Full 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 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