India’s weather is extremely varied, something you must take into account when planning your trip. The most influential feature of the Subcontinent’s climate is the wet season, or monsoon. This breaks on the Keralan coast at the end of May, working its way northeast across the country over the following month and a half. While it lasts, regular and prolonged downpours are interspersed with bursts of hot sunshine, and the pervasive humidity can be intense. At the height of the monsoon – especially in the jungle regions of the northwest and the low-lying delta lands of Bengal – flooding can severely disrupt communications, causing widespread destruction. In the Himalayan foothills, landslides are common, and entire valley systems can be cut off for weeks.
By September, the monsoon has largely receded from the north, but it takes another couple of months before the clouds disappear altogether from the far south. The east coast of Andhra Pradesh and Tamil Nadu, and the south of Kerala, get a second drenching between October and December, when the “northwest” or “retreating” monsoon sweeps in from the Bay of Bengal. By December, however, most of the Subcontinent enjoys clear skies and relatively cool temperatures.
Mid-winter sees the most marked contrasts between the climates of north and south India. While Delhi, for example, may be ravaged by chill winds blowing off the snowfields of the Himalayas, the Tamil plains and coastal Kerala, more than 1000km south, still stew under fierce post-monsoon sunshine. As spring gathers pace, the centre of the Subcontinent starts to heat up again, and by late March thermometers nudge 33°C across most of the Gangetic Plains and Deccan plateau. Temperatures peak in May and early June, when anyone who can retreats to the hill stations. Above the baking Subcontinental land mass, hot air builds up and sucks in humidity from the southwest, causing the onset of the monsoon in late June, and bringing relief to millions of overheated Indians.
The best time to visit most of the country, therefore, is during the cool, dry season, between November and March. Delhi, Agra, Varanasi, Rajasthan and Madhya Pradesh are ideal at this time, and temperatures in Goa and central India remain comfortable. The heat of the south is never less than intense but it becomes stifling in May and June, so aim to be in Tamil Nadu and Kerala between January and March. From this time onwards, the Himalayas grow more accessible, and the trekking season reaches its peak in August and September while the rest of the Subcontinent is being soaked by the rains.