Explanation:

Amritsar and Shimla are two cities in India that are almost on the same latitude, which means they are at similar distances from the equator. However, despite this similarity, they have different climates. The difference in their climates can be attributed to the difference in their altitudes.

Altitude as the main factor:
The primary reason for the difference in climate between Amritsar and Shimla is the difference in their altitudes. Altitude refers to the height or elevation of a place above sea level. Amritsar is located in the state of Punjab, which is in the northern part of India and has an average elevation of around 234 meters above sea level. On the other hand, Shimla is the capital city of the state of Himachal Pradesh, located in the foothills of the Himalayas, and has an average elevation of around 2,205 meters above sea level.

Effect of altitude on climate:
Altitude has a significant impact on climate. As we go higher in altitude, the temperature decreases. This is because the air becomes thinner at higher altitudes, which means it can hold less heat. Therefore, places at higher altitudes tend to be colder than places at lower altitudes. This explains why Shimla, with its higher altitude, has a cooler climate compared to Amritsar.

Other factors:
While altitude is the primary factor influencing the climate difference between Amritsar and Shimla, there are other factors that can also contribute to the variations in their climates. These factors include:

- Distance from the sea: Shimla is located further inland and is farther away from the coast compared to Amritsar. The presence of large water bodies, such as oceans and seas, can influence the climate by moderating temperatures and humidity. Therefore, Amritsar, being closer to the coast, may have a slightly different climate compared to Shimla.

- Snowfall in Shimla: Due to its higher altitude and colder climate, Shimla experiences snowfall during the winter months. This is not the case in Amritsar, which has a lower altitude and a warmer climate.

- Pollution in Amritsar: While pollution can affect local weather conditions, it is unlikely to be the main reason for the climate difference between Amritsar and Shimla. Pollution levels can vary between cities and can have localized effects, but the overall climate patterns are primarily determined by geographical and meteorological factors such as altitude, proximity to the sea, and prevailing wind patterns.

In conclusion, the main reason for the climate difference between Amritsar and Shimla is the difference in their altitudes. Altitude affects temperature, and since Shimla is at a higher altitude compared to Amritsar, it has a cooler climate. Other factors such as distance from the sea, snowfall in Shimla, and pollution in Amritsar may also contribute to the climate variations but to a lesser extent.