What factor causes the highest tides during a full moon?

The highest tides during a full moon are primarily caused by the alignment of the sun, moon, and Earth. During a full moon, the Earth is positioned between the sun and the moon, allowing the gravitational forces of both the sun and the moon to combine effectively. This alignment results in what are called spring tides, which occur when the gravitational pull from the sun and moon works together to exert stronger influences on the Earth's oceans, leading to higher high tides and lower low tides.

While the other factors, such as the proximity of the moon to the Earth and gravitational effects from the sun, contribute to tidal patterns, the alignment specifically during a full moon intensifies the overall tidal range the most. Seasonal changes in temperature do not have a significant effect on the tide heights themselves but can influence the overall conditions of the oceans and coastal regions.