The reason why Delhi feels more comfortable than Kolkata even though the temperature is the same: Calcutta is closer to the sea than Delhi, so the air has more water vapour. So even though the temperature is the same, the sweat evaporates slowly in Kolkata, resulting in suffering. But since Delhi is far from the sea, the air has less water vapour. So sweat evaporates quickly in Delhi. In this case, it feels comfortable because it takes the heat needed for evaporation from the body.
