Spring tides occur twice a month during the full and new moons. Spring tides are the result of the alignment of the Sun, Moon and Earth and the effects of their gravitational forces. Spring tides are also high tides.
A rare type of spring tide is a perigean spring tide: it occurs only a few times a year. The occurrence of this high tide type is due to the new or full moon being at its closest distance to the Earth.
Another type of tide, the neap tide, occurs twice per month. However, this tide type occurs when the Moon's and Sun's gravitational forces form a 90-degree angle with respect to the Earth. Neap tides happen during the first and third quarter moons.