Nature / Earth / Coasts and water
Why spring tides have nothing to do with spring
The Moon and Sun help change the range between high and low water. The season is not the deciding factor.
A spring tide is part of the Moon’s cycle, not a feature of the spring season. Around new and full moons, the Sun, Moon and Earth lie approximately along a line. Their combined tide-producing effects tend to make the difference between high and low water larger. These spring tides occur throughout the year. NOAA explains the spring–neap cycle.
The key idea is range
Tidal range is the vertical difference between high tide and low tide. NOAA describes tides as long-period waves responding to forces from the Moon and Sun; at a coast, we see their arrival as changing sea level. “Spring” therefore describes a larger range, not one unusually large breaking wave. Read NOAA’s definition of tides.
Imagine high water at 4.2 metres and low water at 0.8 metres, both measured from the same reference level. Subtracting 0.8 from 4.2 gives a 3.4-metre range. Those numbers are an invented arithmetic example, not observations from a beach. Comparing heights from different reference levels would not produce the same meaningful calculation.
What changes at a neap tide?
Near the first and third quarters of the lunar cycle, the Sun and Moon lie approximately at right angles as seen from Earth. Their tide-producing effects partly counteract each other. The typical range becomes smaller: high waters are lower and low waters higher than during spring tides. These are neap tides. A quarter Moon looks roughly half illuminated; the phase name describes progress through the cycle. See NOAA’s explanation of quarter-moon tides.
| Pattern | Around which phases? | Typical range |
|---|---|---|
| Spring | New and full Moon | Larger |
| Neap | First and third quarters | Smaller |
The coast adds another pattern
The spring–neap cycle does not tell you how many high tides a particular coast gets in a day. NOAA distinguishes diurnal tides, with one high and one low per lunar day; semidiurnal tides, with two roughly equal highs and lows; and mixed semidiurnal tides, with two highs and lows of unequal height. Continents and ocean basins complicate the water’s response. Compare NOAA’s tidal-cycle descriptions.
Keep those two questions separate: how does the range change through the lunar cycle, and what is the daily pattern at this place? A Moon-phase diagram helps with the first. It cannot supply the local times and heights needed for the second. Use a relevant official local tide prediction for an actual coastal visit; this explainer is not a navigation forecast.
Sources and scope
The linked NOAA explanations were read on 26 September 2026. They come from the same agency and should not be counted as independent confirmations. The illustration is conceptual and the numerical example is ours. Continue through the Nature / Earth reading path.