What effect causes the desert like conditions on the leeward side of mountains, as shown in this chart

The area with the desert-like conditions is called a rain shadow. The mountains block the passage of rain-carrying clouds, which are carried upwards by the wind. The moisture condenses and precipitates before it can cross the mountaintops, so they can't deliver rain to the area on the leeward side of the mountains.

answer; seasons change because earth tilts on its axis; and the angle of the tilt causes the northern and southern hemisphere to trade places throughout the year;