Tides Today & Tomorrow in Portsmouth, NH

TIDE TIMES for Wednesday, August 12, 2026
The tide is currently falling in Portsmouth, NH.
Next low tide : in 1h 39m at 5:24 am (-0.8 ft)
Next high tide : 11:43 am (8.2 ft)
Sunset today : 7:50 pm
Sunrise tomorrow : 5:45 am
Moon phase : New Moon (0% illuminated)
Tide Station Location : Station #8423745
Common Questions About Tides

Portsmouth, NH Tides - Dec 2090

DateHigh TideLow TideSunMoonDate
AMftPMftAMftPMftRiseSet
1Fri7:057.57:287.212:391.01:161.26:554:09Waxing Gibbous1Fri
2Sat7:547.78:207.31:311.12:080.96:564:08Waxing Gibbous2Sat
3Sun8:398.09:077.42:171.02:530.66:574:08Waxing Gibbous3Sun
4Mon9:208.29:507.52:590.93:350.36:584:08Waxing Gibbous4Mon
5Tue9:588.410:317.63:380.84:130.16:594:08Full Moon5Tue
6Wed10:368.611:117.74:160.74:51-0.27:004:08Full Moon6Wed
7Thu11:148.811:507.84:540.55:30-0.47:014:08Full Moon7Thu
8Fri11:528.95:340.46:09-0.57:024:07Full Moon8Fri
9Sat12:307.912:339.06:160.46:51-0.67:034:07Waning Gibbous9Sat
10Sun1:128.01:178.97:000.37:35-0.67:034:08Waning Gibbous10Sun
11Mon1:578.02:048.87:480.38:24-0.57:044:08Waning Gibbous11Mon
12Tue2:468.12:588.68:410.49:16-0.47:054:08Third Quarter12Tue
13Wed3:418.13:578.49:390.410:11-0.37:064:08Third Quarter13Wed
14Thu4:398.25:008.210:410.311:10-0.17:074:08Third Quarter14Thu
15Fri5:398.46:068.111:460.27:074:08Third Quarter15Fri
16Sat6:408.67:138.112:11-0.112:530.07:084:09Waning Crescent16Sat
17Sun7:418.98:178.21:13-0.11:58-0.47:094:09Waning Crescent17Sun
18Mon8:389.29:168.32:13-0.12:57-0.77:094:09Waning Crescent18Mon
19Tue9:329.410:108.43:09-0.23:51-1.07:104:10New Moon19Tue
20Wed10:239.511:028.54:01-0.34:42-1.17:104:10New Moon20Wed
21Thu11:129.511:518.44:51-0.25:31-1.17:114:11New Moon21Thu
22Fri11:599.45:39-0.16:17-1.07:114:11New Moon22Fri
23Sat12:388.312:459.16:260.17:02-0.77:124:12Waxing Crescent23Sat
24Sun1:238.11:298.87:120.37:46-0.47:124:12Waxing Crescent24Sun
25Mon2:087.92:158.37:580.68:300.07:124:13Waxing Crescent25Mon
26Tue2:547.73:027.98:460.89:160.37:134:14Waxing Crescent26Tue
27Wed3:427.53:537.59:371.110:020.77:134:14First Quarter27Wed
28Thu4:317.44:467.210:301.210:510.97:134:15First Quarter28Thu
29Fri5:207.45:416.911:251.311:411.17:134:16First Quarter29Fri
30Sat6:117.46:386.812:221.37:144:17First Quarter30Sat
31Sun7:037.57:356.812:331.21:201.17:144:18Waxing Gibbous31Sun
DateHigh TideLow TideSunMoonDate
AMftPMftAMftPMftRiseSet
Tidal Data Source: (8423745)

Common Questions About Portsmouth, NH Tides

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What time does the tide turn (slack tide) in Portsmouth, NH today?

Slack tide in Portsmouth, NH is approximately 8:33 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 Portsmouth, NH?

Portsmouth, NH is currently in a spring phase. Tonight's moon is 0% 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 maximum.

What datum are Portsmouth, NH 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 Portsmouth, NH?

Tide predictions for Portsmouth, NH 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 Portsmouth, NH?

Tide data for Portsmouth, NH is sourced from NOAA Station #8423745. View the official NOAA station page at https://tidesandcurrents.noaa.gov/stationhome.html?id=8423745.

What is the moon phase in Portsmouth, NH tonight?

Tonight the moon over Portsmouth, NH is New Moon (0% illuminated). This places Portsmouth, NH in a spring tide cycle, so tidal ranges are near their weekly maximum 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