India''s shape, unusual topography, and geographical position give it a diverse climate. Most of India has a tropical or subtropical climate, with little variation in temperature between seasons. The northern plains, however, have a greater temperature range, with cooler winters and hotter summers. The mountain areas have cold winters and cool summers. As elevations increase sharply in the mountains, climate type can change from subtropical to polar within a few miles.
Indias seasonal cycle includes three main phases: the cool, dry winter from October to March; the hot, dry summer from April to June; and the southwest monsoon season of warm, torrential rains from mid-June to September. India
s winter season brings cold temperatures to the mountain slopes and northern plains; temperatures in the Thar Desert reach freezing at night. Farther south, temperatures are mild. Average daily temperatures in January range from 13� to 27�C (55� to 81�F) in the northeastern city of Kolkata (formerly Calcutta); from 8� to 21�C (46� to 70�F) in the north central city of New Delhi; from 19� to 30�C (67� to 85�F) in the west central coast city of Mumbai (formerly Bombay); and from 19� to 29�C (67� to 85�F) in the vicinity of Chennai (formerly Madras) on the southeastern coast. Dry weather generally accompanies the cool winter season, although severe storms sometimes traverse the country, yielding slight precipitation on the northern plains and heavy snowfall in the Himalayas.
India''s hot and dry season reaches its peak during May, when temperatures as high as 49�C (120�F) are commonly recorded in the northern plains. Temperatures in the southern peninsula are somewhat lower, averaging 35� to 40�C (95� to 104�F). At higher altitudes, as in the Western Ghats and the Himalayas, temperatures are considerably cooler.
The average annual rainfall for India as a whole is 1,250 mm (49 in). The heaviest rainfall occurs along the Western Ghats, often more than 3,175 mm (125 in), and on the slopes of the eastern Himalayas and the Khāsi Hills (of Meghalaya), where the town of Cherrapunji receives 10,900 mm (430 in) annually. The entire northeast region averages more than 2,000 mm (80 in) annually, with Jharkhand, Orissa, and the Bengal region receiving nearly as much. Rain and snow fall in abundance on the entire Himalayan range. New Delhi receives an annual average of 800 to 1,000 mm (32 to 40 in) of rain, and the broad swath of land extending to the south, much of it in the rain shadow of the Western Ghats, receives about the same or a little more.