Why is shimla cooler than ludhiana?

Shimla is cooler than Ludhiana because shimla is a hill station and ludhiana lies on the land surface.The temperature of a place is determined by it altitude or height above the sea level. On climbing every 166 metres, there is fall of 1°C in temperature. Whereas the altitude of Shimla is 2205 metres and that of Ludhiana is 255m mts. It is thus, obvious that Shimla will be cooler than Ludhiana.