Portsmouth, NH Tide Chart
Today's high and low tide times for Portsmouth, NH — see the next high and low tide, water heights, and a live tide chart, straight from NOAA.
Tide chart
Pick the number of days with Days · hold or Zoom out to slide to other dates · tap the curve for exact heights.
The dark bands are night. Heights are in feet above MLLW, and times are the station's own local time. Not a flood, navigation, or public-safety forecast.
Tide times and predicted heights: NOAA CO-OPS.
Prefer a plain list? The tide finder below shows every high and low as an accessible table, with a CSV download.
Portsmouth tide times for Wednesday, July 29
| Tide | Time | Height |
|---|---|---|
| Low tide | 5:59 AM | 0.4 ft |
| High tide | 12:14 PM | 8.0 ft |
| Low tide | 5:58 PM | 1.3 ft |
Predicted heights above MLLW (mean lower low water), in Portsmouth local time, from NOAA station 8423898. For any other day, use the chart above. Refreshed daily.
Next king tides
The biggest predicted tides of the coming year at this station, and the lowest-water windows that typically follow — periods with some of the highest predicted astronomical tides of the year. Consult official local forecasts and alerts before planning any beach, boating or shoreline activity.
Computed from a full year of NOAA predictions: the top 10% of high tides, grouped into date windows.
Sun & moon
Find high tides by date
The next 5 days to start — every high and low. Add 5 more days as many times as you like, or pick any range up to a year out.
What the tides are like at Portsmouth
Portsmouth has two high tides and two low tides most days — a semidiurnal tide pattern, cycling roughly every 6 hours 12 minutes. In other words, the two highs each day are usually close in height. The tidal range here is moderate to large, commonly 8 to 9 feet. For the exact heights and times today, read them straight off the live chart above — it's drawn from NOAA's harmonic prediction for this station.
About this station
NOAA station 8423898 (Fort Point) sits at 43.07, -70.71 on the New England coast. Predictions on this page come straight from NOAA's harmonic model for this station — heights in feet above MLLW, times in the station's local time. Conditions a few miles along the shore can differ, so pick the station nearest where you'll actually be.
Nearest stations: Portland, ME (47 mi) · Boston, MA (53 mi) · Providence, RI (94 mi) · Woods Hole, MA (107 mi) · Newport, RI (112 mi)
Official source
For anything safety-related, go straight to NOAA's own prediction page for this station, not this page:
More tide stations
How many tides a day does Portsmouth, NH get?
Portsmouth typically gets two high tides and two low tides each day — a semidiurnal pattern. Exact times for today are on the live chart above.
What is the tidal range at Portsmouth, NH?
The range between low and high water at Portsmouth is moderate to large, commonly 8 to 9 feet. The chart above shows the exact predicted heights for the days you pick, straight from NOAA station 8423898.
Where does the tide data come from?
Straight from NOAA CO-OPS, the official U.S. source for tide predictions — for Portsmouth, NH it uses the NOAA station listed above. Heights are in feet above MLLW (mean lower low water, the standard chart datum) and times are shown in the station's own local time.
How far ahead can I see the tides?
Tide predictions are computed from astronomy (the positions of the moon and sun), so they're available about a year ahead. Use the date-range finder to list every high tide between any two dates — for general reference and low-risk scheduling only. Before any marine or shoreline activity, confirm conditions with official local forecasts, alerts, harbor guidance, and NOAA.
What is a king tide?
An informal name for the highest tides of the year, which happen when a new or full moon lines up with the moon's closest approach to Earth. In the finder, the top 10% highest tides in your range are marked with a crown — periods with some of the highest predicted astronomical tides of the year.
What actually makes the tide bigger or smaller?
The engine is gravity: the moon and sun pull the ocean into bulges. When they line up at a new or full moon you get the biggest swings (spring tides); at quarter moons their pulls partly cancel (neap tides), and the moon's closest approach (perigee) super-sizes things further — that's a king tide. River flow, the shape of the bay, and long-term sea-level cycles can also affect the actual water level, which is why real conditions can differ from the astronomical prediction shown here.
What are the highest tides in the world — and in the U.S.?
The world's largest tides are in Canada's Bay of Fundy, where the range between low and high can top 50 feet (it's outside NOAA's network, so it isn't listed here). In the U.S., the giants are Alaska's Cook Inlet — Anchorage sees swings around 26–30 feet — along with Southeast Alaska ports like Skagway, and on the East Coast, Eastport, Maine at roughly 18 feet. All of those have dedicated pages here.
Can I save my home beach and other spots I follow?
Yes — tap ＋ Add to Saved Stations next to any station's name (it turns into a green Saved note), or ＋ Add nearest inside the Saved Stations dropdown to add the station closest to you (allow location access). Your saved spots appear as one-tap cards on the tides home page, the Default column's radio button picks your primary station, and Edit removes stations. Everything is stored on your device; no account needed.
Is this free? Do I need an account?
Completely free, no sign-up. It's built on public NOAA data and works on any device.