Tides Today & Tomorrow in Portsmouth, NH

TIDE TIMES for Sunday, August 16, 2026
The tide is currently falling in Portsmouth, NH.
Next low tide : in 1h 36m at 8:59 pm (0.0 ft)
Next high tide (tomorrow) : 3:17 am (8.4 ft)
Sunset today : 7:44 pm
Sunrise tomorrow : 5:50 am
Moon phase : Waxing Crescent (18% illuminated)
Tide Station Location : Station #8423745
Common Questions About Tides

Portsmouth, NH Tides - Jan 1961

DateHigh TideLow TideSunMoonDate
AMftPMftAMftPMftRiseSet
1Sun10:598.611:347.64:410.65:17-0.27:144:18Full Moon1Sun
2Mon11:378.55:190.75:54-0.27:144:19Full Moon2Mon
3Tue12:127.612:138.45:560.76:29-0.17:144:20Full Moon3Tue
4Wed12:487.612:498.36:310.87:030.07:144:21Waning Gibbous4Wed
5Thu1:237.51:248.27:080.87:380.17:144:22Waning Gibbous5Thu
6Fri1:597.42:028.07:460.98:150.27:144:23Waning Gibbous6Fri
7Sat2:377.42:437.88:281.08:550.47:144:24Waning Gibbous7Sat
8Sun3:187.43:287.59:141.09:380.57:144:25Third Quarter8Sun
9Mon4:027.54:177.410:031.010:250.67:134:26Third Quarter9Mon
10Tue4:507.65:127.210:560.911:150.77:134:27Third Quarter10Tue
11Wed5:417.86:117.211:540.77:134:28Third Quarter11Wed
12Thu6:378.17:137.312:110.612:550.47:134:29Waning Crescent12Thu
13Fri7:358.58:157.61:090.51:56-0.17:124:31Waning Crescent13Fri
14Sat8:319.09:128.02:080.22:53-0.77:124:32Waning Crescent14Sat
15Sun9:269.510:078.43:04-0.23:48-1.27:114:33New Moon15Sun
16Mon10:219.911:018.73:59-0.64:41-1.67:114:34New Moon16Mon
17Tue11:1510.111:559.04:53-0.85:33-1.87:104:35New Moon17Tue
18Wed12:0810.15:47-1.06:25-1.87:104:37Waxing Crescent18Wed
19Thu12:479.11:0210.06:41-1.07:17-1.77:094:38Waxing Crescent19Thu
20Fri1:399.11:569.67:35-0.98:09-1.37:084:39Waxing Crescent20Fri
21Sat2:338.92:539.08:33-0.69:04-0.97:084:40Waxing Crescent21Sat
22Sun3:308.73:538.59:33-0.310:00-0.47:074:42First Quarter22Sun
23Mon4:288.54:557.910:360.110:580.27:064:43First Quarter23Mon
24Tue5:268.25:597.511:400.311:590.67:054:44First Quarter24Tue
25Wed6:268.17:037.212:460.47:044:45Waxing Gibbous25Wed
26Thu7:268.08:057.11:010.81:490.47:044:47Waxing Gibbous26Thu
27Fri8:228.08:597.22:000.92:450.37:034:48Waxing Gibbous27Fri
28Sat9:128.19:487.32:520.93:330.17:024:49Waxing Gibbous28Sat
29Sun9:568.210:317.43:380.84:170.07:014:51Waxing Gibbous29Sun
30Mon10:388.311:117.54:200.74:56-0.17:004:52Full Moon30Mon
31Tue11:168.411:487.64:580.65:31-0.16:594:53Full Moon31Tue
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 12:08 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 18% 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 (18% 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