Pune is colder than Mumbai, because Pune does not have the moderating influence of the sea which Mumbai experiences. Mumbai is a coastal area, whereas Pune is interior and not a coastal area.
The climate is equitable in coastal areas. The extremes of climate can be noticed in areas which are far away from the coastal areas. Although there is not much variation in the temperature in the coastal areas, there is considerable variation in the rainfall pattern. Seasonal variations are more in the interiors of India. Ocean currents along with onshore winds affect the climate of the coastal areas.
If the winds are onshore, the coastal areas will be cooled or warmed if cold or warm currents flow past any coastal areas.