When do spring tides occur? spring tides They occur on the date of the vernal equinox each year, no matter what stage the moon is in. This is why they are called O They occur when the sun, moon, and Earth are at 45-degree angles from each other. This happens once every spring They occur when the sun, moon, and Earth are aligned. In spite of their name, these tides occur twice a year in the spring and fall They occur when the sun, ​