How to Read NOAA Tide Predictions

If you spend time on the water — fishing, kayaking, boating, or simply exploring the coast — understanding NOAA tide predictions is one of the most practical skills you can develop. NOAA (the National Oceanic and Atmospheric Administration) publishes highly accurate tide data for thousands of stations across the U.S. coastline, and knowing how to read that data can mean the difference between a great day on the water and a dangerous one.

What Are NOAA Tide Predictions?

NOAA tide predictions are scientifically computed forecasts of water level changes at specific coastal locations. They're based on harmonic analysis of historical tidal observations, accounting for the gravitational pull of the moon and sun, local geography, and seasonal patterns. NOAA publishes predictions for over 3,000 reference and subordinate stations across the U.S.

Each prediction shows:

• High tide times and heights — when water reaches its peak level
• Low tide times and heights — when water reaches its lowest point
• Water level in feet or meters relative to Mean Lower Low Water (MLLW), the standard tidal datum

Understanding the Tide Table Format

A standard NOAA tide table lists predictions in chronological order for each day. Here's how to read a typical entry:

• Date and time — given in local standard time (LST) or local daylight time (LDT)
• Height — water level in feet above MLLW. A negative value means the water is below the average low-water mark — important for shallow-draft boaters and clam diggers.
• High/Low indicator — H for high tide, L for low tide

Most coastal locations experience two high tides and two low tides per day (semidiurnal pattern), though some areas — particularly along the Gulf Coast — see a mixed or diurnal pattern with one dominant high and low per day.

Key Terms to Know

• MLLW (Mean Lower Low Water) — the average of the lower of the two daily low tides over a 19-year tidal epoch. This is the zero reference point for NOAA charts.
• Tidal range — the difference in height between high and low tide. Ranges vary dramatically by location: less than 1 foot in parts of the Gulf of Mexico, over 40 feet in the Bay of Fundy.
• Slack water — the brief period around high or low tide when current is minimal. Critical for divers and anglers.
• Tidal current vs. tide height — tide height tells you water level; tidal current tells you flow direction and speed. NOAA publishes separate current predictions.

How to Use NOAA Predictions for Coastal Activities

Reading the numbers is only half the equation. Here's how to apply them:

• Fishing: Many species feed aggressively during tidal movement — the two hours before and after a tide change are often the most productive windows.
• Kayaking and paddleboarding: Plan launches and returns around low-current slack periods. Avoid paddling against a strong ebb or flood current.
• Boating: Check predicted depths at low tide against your vessel's draft. Add a safety margin — storm surge, wind, and barometric pressure can push actual water levels below predicted lows.
• Beach access: Rocky beaches, tide pools, and sandbars are most accessible within two hours of low tide.

The Limitation of Predictions — and Why Real-Time Data Matters

NOAA tide predictions are computed months in advance and don't account for real-time conditions. Wind, storm surge, barometric pressure, and river discharge can all cause actual water levels to deviate significantly from predictions — sometimes by a foot or more.

That's why serious coastal users pair predicted tides with live NOAA data. The Tidesy L, Tidesy M, and Tidesy S displays pull live NOAA tide predictions, weather, and coastal alerts directly to an always-on screen — no app, no phone, no subscription required. You get the full picture at a glance, whether you're at the dock, in the garage, or planning the next morning's launch.

Finding Your NOAA Station

NOAA's Tides and Currents website (tidesandcurrents.noaa.gov) lets you search by location, zip code, or station name. Each station page shows a tide chart, tabular predictions, and real-time water level data where available. Bookmark your nearest station — or better yet, put it on your wall with a Tidesy display that updates automatically.

Bottom Line

NOAA tide predictions are the gold standard for coastal planning. Learning to read them — understanding tidal datums, semidiurnal vs. diurnal patterns, and the difference between predicted and observed levels — makes every trip safer and more productive. Pair that knowledge with a live data display and you're operating with the full picture, every time.