New Delhi has a wide-ranging climate. Summer in northern India is very hot, and often humid, with temperatures as high as 48C (118F) seen regularly from May to June. It is advisable to wear light shoes and loose-fitted cotton clothes that cover your arms and legs, protecting you from both sun and insects.
The July and August monsoon months that follow are quite humid. Expect temperatures ranging from 32C to 38C (90F to 100F) with moderate showers.
The months between September and November are the best months to visit Delhi, with cool, dry temperatures ranging between 24C and 28C (75F to 82F). Expect cooler temperatures of 3C – 18C (37F-65F) between November and February, when gloves and wool clothes are useful.