Tides Today & Tomorrow in Merrimack River Entrance, MA

TIDE TIMES for Tuesday, July 21, 2026
The tide is currently falling in Merrimack River Entrance, MA.
Next low tide : in 4h 55m at 11:40 am (0.6 ft)
Next high tide : 5:57 pm (8.4 ft)
Sunset today : 8:15 pm
Sunrise tomorrow : 5:23 am
Moon phase : First Quarter (52% illuminated)
Tide Station Location : Station #8440452
Common Questions About Tides

Merrimack River Entrance, MA Tides - Jul 2074

DateHigh TideLow TideSunMoonDate
AMftPMftAMftPMftRiseSet
1Sun5:038.45:398.311:240.111:520.75:098:25First Quarter1Sun
2Mon5:598.36:348.612:170.25:098:25First Quarter2Mon
3Tue6:598.27:308.912:510.41:130.25:108:25First Quarter3Tue
4Wed8:008.18:289.21:520.12:100.25:108:24Waxing Gibbous4Wed
5Thu9:018.29:249.62:53-0.23:070.15:118:24Waxing Gibbous5Thu
6Fri9:598.310:189.93:51-0.64:020.05:128:24Waxing Gibbous6Fri
7Sat10:558.411:1210.04:47-0.94:560.05:128:24Full Moon7Sat
8Sun11:498.55:40-1.15:50-0.15:138:23Full Moon8Sun
9Mon12:0410.112:418.66:32-1.16:42-0.15:148:23Full Moon9Mon
10Tue12:5610.01:318.67:22-1.17:330.05:158:22Waning Gibbous10Tue
11Wed1:469.82:218.58:11-0.98:240.15:158:22Waning Gibbous11Wed
12Thu2:359.53:108.48:59-0.69:150.35:168:21Waning Gibbous12Thu
13Fri3:259.04:008.39:48-0.310:070.55:178:21Waning Gibbous13Fri
14Sat4:168.64:508.210:370.011:010.75:188:20Third Quarter14Sat
15Sun5:098.15:418.111:260.411:560.95:198:19Third Quarter15Sun
16Mon6:027.76:338.012:170.75:198:19Third Quarter16Mon
17Tue6:577.47:258.012:511.01:091.05:208:18Third Quarter17Tue
18Wed7:537.28:178.01:481.02:011.25:218:17Waning Crescent18Wed
19Thu8:487.19:078.12:430.92:531.35:228:16Waning Crescent19Thu
20Fri9:397.19:558.23:340.83:411.35:238:16Waning Crescent20Fri
21Sat10:277.210:408.44:220.64:271.25:248:15Waning Crescent21Sat
22Sun11:127.311:238.55:070.55:111.25:258:14New Moon22Sun
23Mon11:557.45:490.35:541.05:268:13New Moon23Mon
24Tue12:058.712:377.66:300.16:360.95:278:12New Moon24Tue
25Wed12:468.81:187.87:11-0.17:180.75:288:11New Moon25Wed
26Thu1:288.91:598.07:51-0.28:020.65:298:10Waxing Crescent26Thu
27Fri2:119.02:438.38:33-0.38:480.45:308:09Waxing Crescent27Fri
28Sat2:578.93:298.59:18-0.39:380.35:318:08Waxing Crescent28Sat
29Sun3:468.84:198.610:06-0.210:320.25:328:07First Quarter29Sun
30Mon4:408.65:128.810:56-0.111:290.25:338:06First Quarter30Mon
31Tue5:378.36:078.911:510.15:348:05First Quarter31Tue
DateHigh TideLow TideSunMoonDate
AMftPMftAMftPMftRiseSet
Tidal Data Source: (8440452)

Common Questions About Merrimack River Entrance, MA Tides

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What time does the tide turn (slack tide) in Merrimack River Entrance, MA today?

Slack tide in Merrimack River Entrance, MA is approximately 2:48 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 Merrimack River Entrance, MA?

Merrimack River Entrance, 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 Merrimack River Entrance, 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 Merrimack River Entrance, MA?

Tide predictions for Merrimack River Entrance, 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 Merrimack River Entrance, MA?

Tide data for Merrimack River Entrance, MA is sourced from NOAA Station #8440452. View the official NOAA station page at https://tidesandcurrents.noaa.gov/stationhome.html?id=8440452.

What is the moon phase in Merrimack River Entrance, MA tonight?

Tonight the moon over Merrimack River Entrance, MA is First Quarter (52% illuminated). This places Merrimack River Entrance, 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