Tides Today & Tomorrow in Portsmouth, NH

TIDE TIMES for Saturday, July 18, 2026
The tide is currently falling in Portsmouth, NH.
Next low tide : in 2h 34m at 9:05 am (-0.7 ft)
Next high tide : 3:28 pm (8.6 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 - May 2066

DateHigh TideLow TideSunMoonDate
AMftPMftAMftPMftRiseSet
1Sat4:317.65:206.910:530.911:041.75:357:44First Quarter1Sat
2Sun5:237.56:106.911:411.011:581.75:347:45First Quarter2Sun
3Mon6:177.47:017.112:321.05:337:46First Quarter3Mon
4Tue7:137.47:527.512:551.51:230.95:317:47Waxing Gibbous4Tue
5Wed8:107.58:417.91:531.22:150.85:307:49Waxing Gibbous5Wed
6Thu9:067.79:288.42:480.73:050.55:297:50Waxing Gibbous6Thu
7Fri9:578.010:139.03:400.13:530.35:277:51Waxing Gibbous7Fri
8Sat10:488.211:009.44:30-0.44:400.05:267:52Full Moon8Sat
9Sun11:388.511:479.85:19-0.95:28-0.25:257:53Full Moon9Sun
10Mon12:298.66:09-1.26:18-0.35:247:54Full Moon10Mon
11Tue12:3710.01:218.67:00-1.47:09-0.35:237:55Waning Gibbous11Tue
12Wed1:2910.02:148.67:52-1.48:03-0.15:227:56Waning Gibbous12Wed
13Thu2:239.83:108.48:46-1.28:590.15:207:57Waning Gibbous13Thu
14Fri3:209.54:108.39:44-0.810:010.35:197:58Waning Gibbous14Fri
15Sat4:229.05:138.210:44-0.511:060.65:188:00Third Quarter15Sat
16Sun5:288.66:158.111:46-0.25:178:01Third Quarter16Sun
17Mon6:338.27:168.212:130.712:470.15:168:02Third Quarter17Mon
18Tue7:398.08:158.31:210.71:480.45:158:03Waning Crescent18Tue
19Wed8:437.89:108.42:270.52:460.65:158:04Waning Crescent19Wed
20Thu9:407.79:598.63:260.33:380.75:148:05Waning Crescent20Thu
21Fri10:327.710:438.64:170.14:240.85:138:06Waning Crescent21Fri
22Sat11:197.611:258.65:040.05:070.95:128:07New Moon22Sat
23Sun12:037.65:460.05:471.05:118:08New Moon23Sun
24Mon12:058.612:447.56:260.06:261.15:108:09New Moon24Mon
25Tue12:438.51:237.57:040.17:031.25:108:10New Moon25Tue
26Wed1:208.52:017.47:410.27:401.35:098:10Waxing Crescent26Wed
27Thu1:578.32:397.38:170.38:181.35:088:11Waxing Crescent27Thu
28Fri2:358.23:187.28:550.48:591.45:088:12Waxing Crescent28Fri
29Sat3:158.03:597.29:350.59:431.55:078:13Waxing Crescent29Sat
30Sun3:587.94:427.310:160.610:311.55:078:14First Quarter30Sun
31Mon4:457.75:277.411:000.711:211.45:068:15First Quarter31Mon
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 12:16 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 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