Tides Today & Tomorrow in Portsmouth, NH

TIDE TIMES for Tuesday, July 21, 2026
The tide is currently falling in Portsmouth, NH.
Next low tide (tomorrow) : in 4h 13m at 12:20 am (0.8 ft)
Next high tide (tomorrow) : 6:35 am (7.2 ft)
Sunset today : 8:16 pm
Sunrise tomorrow : 5:22 am
Moon phase : First Quarter (52% illuminated)
Tide Station Location : Station #8423745
Common Questions About Tides

Portsmouth, NH Tides - Oct 2067

DateHigh TideLow TideSunMoonDate
AMftPMftAMftPMftRiseSet
1Sat6:517.07:077.612:300.912:431.66:406:24Third Quarter1Sat
2Sun7:507.08:067.61:301.01:461.56:416:22Waning Crescent2Sun
3Mon8:447.29:017.72:271.02:431.46:426:20Waning Crescent3Mon
4Tue9:327.49:497.83:170.93:331.16:446:19Waning Crescent4Tue
5Wed10:147.710:327.93:590.84:160.86:456:17Waning Crescent5Wed
6Thu10:528.011:128.04:360.64:560.56:466:15New Moon6Thu
7Fri11:288.211:508.15:110.65:320.36:476:13New Moon7Fri
8Sat12:028.45:440.56:080.16:486:12New Moon8Sat
9Sun12:278.112:358.66:180.56:450.06:496:10New Moon9Sun
10Mon1:048.01:108.76:540.57:22-0.16:516:08Waxing Crescent10Mon
11Tue1:417.91:478.77:310.68:03-0.16:526:07Waxing Crescent11Tue
12Wed2:217.82:288.78:120.68:470.06:536:05Waxing Crescent12Wed
13Thu3:067.63:158.68:580.79:370.16:546:03Waxing Crescent13Thu
14Fri3:577.54:098.59:500.810:330.26:556:02First Quarter14Fri
15Sat4:557.45:108.410:480.911:330.26:566:00First Quarter15Sat
16Sun5:587.56:158.411:520.96:585:58First Quarter16Sun
17Mon7:027.77:238.412:360.212:590.76:595:57Waxing Gibbous17Mon
18Tue8:068.18:298.61:390.12:070.37:005:55Waxing Gibbous18Tue
19Wed9:058.69:318.82:41-0.13:10-0.27:015:54Waxing Gibbous19Wed
20Thu9:599.110:278.93:37-0.34:08-0.67:025:52Waxing Gibbous20Thu
21Fri10:499.411:219.04:29-0.55:01-1.07:045:50Full Moon21Fri
22Sat11:389.75:18-0.55:52-1.27:055:49Full Moon22Sat
23Sun12:129.012:259.76:06-0.46:41-1.27:065:47Full Moon23Sun
24Mon1:018.81:129.56:53-0.27:29-0.97:075:46Waning Gibbous24Mon
25Tue1:508.51:589.27:390.28:17-0.67:095:44Waning Gibbous25Tue
26Wed2:388.12:458.88:260.59:06-0.27:105:43Waning Gibbous26Wed
27Thu3:287.73:358.49:150.99:570.37:115:41Waning Gibbous27Thu
28Fri4:217.44:298.010:081.310:510.77:125:40Third Quarter28Fri
29Sat5:167.25:267.611:051.511:460.97:145:39Third Quarter29Sat
30Sun6:117.16:237.412:031.67:155:37Third Quarter30Sun
31Mon7:057.17:217.312:411.11:031.67:165:36Third Quarter31Mon
DateHigh TideLow TideSunMoonDate
AMftPMftAMftPMftRiseSet
Tidal Data Source: (8423745)

Common Questions About Portsmouth, NH Tides

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

Slack tide in Portsmouth, NH is approximately 3:27 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 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 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 First Quarter (52% illuminated). This places Portsmouth, NH 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