Tides Today & Tomorrow in Portsmouth, NH

TIDE TIMES for Saturday, August 15, 2026
The tide is currently falling in Portsmouth, NH.
Next low tide : in 31m at 8:09 pm (-0.2 ft)
Next high tide (tomorrow) : 2:28 am (8.9 ft)
Sunset today : 7:45 pm
Sunrise tomorrow : 5:49 am
Moon phase : Waxing Crescent (11% illuminated)
Tide Station Location : Station #8423745
Common Questions About Tides

Portsmouth, NH Tides - Jan 1963

DateHigh TideLow TideSunMoonDate
AMftPMftAMftPMftRiseSet
1Tue3:018.13:138.68:560.39:30-0.57:144:18First Quarter1Tue
2Wed3:558.24:138.39:550.310:25-0.37:144:19First Quarter2Wed
3Thu4:538.35:168.110:570.211:23-0.17:144:20First Quarter3Thu
4Fri5:528.46:227.912:030.17:144:21First Quarter4Fri
5Sat6:538.67:307.812:240.11:10-0.17:144:22Waxing Gibbous5Sat
6Sun7:548.98:337.91:260.12:14-0.47:144:22Waxing Gibbous6Sun
7Mon8:519.19:318.02:260.13:13-0.77:144:23Waxing Gibbous7Mon
8Tue9:449.310:258.13:220.04:06-0.97:144:25Full Moon8Tue
9Wed10:359.311:168.24:140.04:57-1.07:144:26Full Moon9Wed
10Thu11:249.35:040.05:45-1.07:134:27Full Moon10Thu
11Fri12:048.112:119.15:510.16:30-0.87:134:28Full Moon11Fri
12Sat12:508.012:568.96:370.27:14-0.57:134:29Waning Gibbous12Sat
13Sun1:337.91:408.57:220.47:56-0.27:124:30Waning Gibbous13Sun
14Mon2:177.72:258.18:080.78:390.17:124:31Waning Gibbous14Mon
15Tue3:027.53:127.78:550.99:230.57:114:32Waning Gibbous15Tue
16Wed3:487.44:027.39:461.110:090.87:114:34Third Quarter16Wed
17Thu4:367.34:557.010:391.310:561.17:104:35Third Quarter17Thu
18Fri5:257.35:516.711:341.311:461.37:104:36Third Quarter18Fri
19Sat6:167.36:506.612:321.27:094:37Third Quarter19Sat
20Sun7:097.47:486.612:401.41:301.07:094:38Waning Crescent20Sun
21Mon8:007.68:406.81:341.42:230.77:084:40Waning Crescent21Mon
22Tue8:488.09:287.12:241.23:090.47:074:41Waning Crescent22Tue
23Wed9:328.310:127.33:100.93:530.07:064:42Waning Crescent23Wed
24Thu10:168.710:557.63:540.64:35-0.47:064:44New Moon24Thu
25Fri10:599.011:377.94:380.35:17-0.77:054:45New Moon25Fri
26Sat11:439.35:230.06:00-1.07:044:46New Moon26Sat
27Sun12:208.212:289.46:09-0.36:44-1.17:034:47Waxing Crescent27Sun
28Mon1:038.41:159.36:56-0.47:29-1.17:024:49Waxing Crescent28Mon
29Tue1:498.62:049.17:46-0.58:16-1.07:014:50Waxing Crescent29Tue
30Wed2:388.72:588.88:40-0.49:08-0.77:004:51First Quarter30Wed
31Thu3:328.63:578.49:38-0.310:02-0.36:594:53First Quarter31Thu
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 11:18 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 Portsmouth, NH?

Portsmouth, NH is currently in a spring phase. Tonight's moon is 11% 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 Waxing Crescent (11% 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