The gravitational pull of the moon mainly controls our tides as it orbits Earth, while local weather and the Sun's gravitational pull on the moon have an impact, too. There are two extremes of the tide: spring tide and neap tide. A spring tide is when the tide height between high and low tide (tidal range) is at its highest, while a neap tide is when the tidal range is at its lowest.
| Tide type | Characteristics | Occurence |
|---|---|---|
| Spring tide | Higher highs, lower lows. Greatest tidal range | ~7 days after a neap tide. Occur in a new and full moon. |
| Neap tide | Lower highs, higher lows. Smallest tidal range | ~7 days after a spring tide. Occur in a first and third quarter moon. |
What is a spring tide?
A spring tide is when the sun and the moon align to create the greatest gravitational pull on the sea. When the Sun and Moon align, their gravitational pull reinforces each other, producing higher high tides and lower low tides (a larger tidal range).
When a spring tide is particularly large, we observe a perigean spring tide. This occurs when a spring tide coincides with the Moon being at perigee, and is commonly referred to as a king tide. These are dependent on the Moon’s distance and local conditions. Perigean spring tides generally occur 1-4 times a year.
The diagram above shows the rotation of the moon around the Earth (red) and the rotation of the Earth around the sun (yellow). When the gravitational forces of the sun and moon combine, they create the greatest tidal bulge (dark blue).
What is a neap tide?
When the sun and moon are at right angles to each other, there is the least gravitational pull, meaning the tidal range is at its lowest. The neap tide occurs 7 days after the spring tide.
Again, the diagram above shows the moon’s rotation around the earth (red) and the Earth’s rotation around the sun (yellow). When the sun and the moon’s gravitational forces are at right angles to each other, they create the least tidal bulge.
When is the next spring tide?
I've previously written about when all the spring (and neap) tides occur. Refer to this page to find out when the next spring tide is.
🌊 See when the next spring and neap tides occurs
đź“… Add spring and neap tides to your calendar
How often do spring tides occur?
Spring tides occur typically twice a month. Depending on how the months fall, some months sometimes see three. In a typical year, you can expect to see around 25 spring tides. As such, the name 'spring' has nothing to do with the season; instead, its name comes from the old term 'springing forth'. They occur roughly 7 days after a neap tide. Spring tides occur during a new or full moon.
How often do neap tides occur?
Neap tides also occur typically twice a month. Neap tides usually occur roughly 7 days after a spring tide. It's believed the word 'neap' originates from an Anglo-Saxon word meaning 'scanty' or 'without power'. Neap tides occur during the first and third quarter moon phases.
Remember, even when there's a neap tide, the sea can be formidable, and you should always check the tide times and the weather before heading out to sea.
Frequently Asked Questions
Do spring tides have anything to do with the season?
No. Spring tides have nothing to do with the spring season. They occur year-round, roughly twice per month. The name comes from the idea of water 'springing forth', meaning to rise or swell.
Are spring tides dangerous?
Spring tides can be more hazardous than average tides because they produce the greatest tidal range and stronger tidal currents. Faster-moving water and rapidly changing water levels can catch beachgoers, anglers, surfers, and boaters off guard.
How often do spring/neap tides happen?
Spring tides occur during the new and full moon phases, while neap tides occur during the first and third quarter moons. They alternate roughly every 7 days as the Moon moves through its phases. The exact timing can vary slightly depending on local conditions.
What’s the difference between tidal range and tide height?
Tide height refers to the height of a single high or low tide, usually measured relative to mean sea level (MSL) or another benchmark. Tidal range is the vertical difference between a high tide and the following low tide.
What is a perigean spring tide?
A perigean spring tide occurs when a spring tide coincides with the Moon being at perigee, which is its closest point to Earth in its orbit. This can produce higher-than-usual high tides. In some regions, exceptionally high perigean spring tides are informally called 'king tides'.
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