Latitude has the greatest impact on determining climate.

Latitude influences the amount of solar energy a region receives, which is the primary factor in determining climate. Areas near the equator (low latitudes) receive more direct sunlight year-round, leading to warmer, tropical climates. In contrast, higher latitudes, closer to the poles, receive less direct sunlight, resulting in colder, polar climates. While altitude, ocean currents, and proximity to mountains also affect climate, latitude is the most fundamental factor because it defines the basic temperature and seasonal patterns experienced by different regions.