Tides Today & Tomorrow in Portsmouth, NH

TIDE TIMES for Saturday, July 18, 2026
The tide is currently rising in Portsmouth, NH.
Next low tide : 9:05 am (-0.7 ft)
Next high tide : in 19m at 2:50 am (9.3 ft)
Sunset today : 8:18 pm
Sunrise tomorrow : 5:20 am
Moon phase : Waxing Crescent (23% illuminated)
Tide Station Location : Station #8423745
Common Questions About Tides

Portsmouth, NH Tides - Feb 2066

DateHigh TideLow TideSunMoonDate
AMftPMftAMftPMftRiseSet
1Mon3:567.94:287.110:100.610:211.06:574:55First Quarter1Mon
2Tue4:487.75:256.711:080.911:151.46:564:57First Quarter2Tue
3Wed5:437.46:266.412:091.06:554:58First Quarter3Wed
4Thu6:427.37:286.412:131.61:121.16:534:59Waxing Gibbous4Thu
5Fri7:407.48:256.51:151.72:110.96:525:01Waxing Gibbous5Fri
6Sat8:347.69:146.82:111.53:000.76:515:02Waxing Gibbous6Sat
7Sun9:217.99:577.03:001.33:430.46:505:03Waxing Gibbous7Sun
8Mon10:038.110:377.33:431.04:210.16:495:05Full Moon8Mon
9Tue10:428.411:147.64:220.74:56-0.16:475:06Full Moon9Tue
10Wed11:208.511:487.95:000.45:30-0.36:465:07Full Moon10Wed
11Thu11:578.65:380.16:04-0.46:455:09Full Moon11Thu
12Fri12:228.212:348.66:17-0.16:39-0.56:435:10Waning Gibbous12Fri
13Sat12:578.41:138.56:57-0.37:17-0.46:425:11Waning Gibbous13Sat
14Sun1:348.61:568.37:41-0.47:58-0.36:405:13Waning Gibbous14Sun
15Mon2:168.72:448.08:28-0.38:450.06:395:14Waning Gibbous15Mon
16Tue3:048.63:387.69:22-0.29:370.36:385:15Third Quarter16Tue
17Wed3:588.54:397.310:210.010:350.66:365:17Third Quarter17Wed
18Thu5:008.45:487.111:260.111:400.76:355:18Third Quarter18Thu
19Fri6:088.37:017.112:370.16:335:19Waning Crescent19Fri
20Sat7:208.48:117.412:510.71:49-0.16:325:20Waning Crescent20Sat
21Sun8:288.79:127.82:010.52:51-0.46:305:22Waning Crescent21Sun
22Mon9:279.010:068.23:040.13:46-0.76:295:23New Moon22Mon
23Tue10:229.210:558.54:00-0.34:36-0.96:275:24New Moon23Tue
24Wed11:129.211:418.84:51-0.65:22-1.06:255:26New Moon24Wed
25Thu11:599.15:40-0.76:05-0.86:245:27New Moon25Thu
26Fri12:248.912:448.86:26-0.76:46-0.56:225:28Waxing Crescent26Fri
27Sat1:058.81:288.47:10-0.57:26-0.16:215:29Waxing Crescent27Sat
28Sun1:458.62:127.97:54-0.28:070.36:195:31Waxing Crescent28Sun
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 5:57 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 transitional phase. Tonight's moon is 23% 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 shifting between spring and neap.

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 (23% illuminated). This places Portsmouth, NH in a transitional tide cycle, so tidal ranges are shifting between spring and neap 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