The Moon affects the Earth's climate

The most obvious effect can be seen in the ocean tides. The Earth's rotation causes the Moon's gravity to pull the water on the closest side of Earth towards it, creating a bulge. The centrifugal force caused by the Earth's rotation makes the sea bulge on the other side too. These bulges of water are high tides.

Every 18.6 years, there is a lunar nodal cycle, where the lunar plane tilts away from the equatorial plane, causing tides to grow smaller. When the Moon's orbit is more in line with the Earth equator, the tides are bigger.