First, the amount of sunlight received at a given latitude is important. At the equator, the sun is high in the sky and thus very intense. As you move away from the equator, the sun does not reach as high of an angle in the sky, and is less intense. Another important effect near the poles is that during the summer, the sun is up all the time, which boosts the total amount of sunlight received in a day, while in contrast, during the winter, no sunlight is received at all.
There is another, more subtle effect that has to do with latitude. Nature likes to have the temperature be the same everywhere, much like ice cream melts at room temperature or a hot cup of coffee cools to room temperature. The equator is getting blasted with intense sunlight, while the poles are getting a lot less. Nature tries to resolve this imbalance and make the atmosphere the same temperature everywhere. The most efficient way to transfer heat towards the poles depends on latitude and the rotation of the Earth in a complex way. In the tropics (within 30 degrees latitude of the equator), the average daily temperature is mostly constant. Whether you move from north to south, say fro the equator to Mexico, the temperature is mostly the same. Compare that to the midlatitudes (30–60 degrees latitude), where the temperature changes rapidly as you move north or south to the poles. For example, the temperature in Texas is a lot hotter than the temperature in North Dakota.
Another factor is the composition of the surface. Different substances absorb, store, and re-emit heat with different levels of efficiency. The ocean is a major factor, which can either warm or cool the adjacent land. Other surface materials like rock, sand, vegetation, and ice also regulate temperature
The elevations of the surface, specifically mountains effect the climate. Usually, the taller the mountain, the colder the temperature is at the top. Mountains also cause air to flow in certain ways around them, which leads to wet areas on the upwind side and dry areas on the downwind side.
