I found this article on the Telegraph (UK) website about Shimla (a very famous town here in India that was the Summer retreat for the Raj):
India's cool colonial hill stations getting hotter every year
For more than a century they were the Himalayan retreats where British officers and their families escaped the summer heat and dust of the plains, but according to new figures India's cool colonial era hill stations are getting hotter every year.
Some towns, like Shimla, served for more than seven decades as the summer capital of British India Photo: GETTY
By Dean Nelson, New Delhi
3:17PM BST 14 Jun 2012
The celebrated 'British' hill towns of Mussoorie and Shimla in Himachal Pradesh have seen summer temperatures rise by more than five degrees in the last forty years, from 28.5C in 1971 to 33.7C in 2011, according to new government figures.
Now the higher temperatures are driving away the well-heeled Indian holiday makers who have flocked to the hills since independence for their shady pine forests, 'English' mall roads and Anglican churches.
The stations were build in the early to mid 19th Century as 'sanatorium' resorts for soldiers and officials to recover from tropical diseases in highland countryside reminiscent of the Britain they had left behind.
Some, like Shimla, which served for more than seven decades as the summer capital of British India, had a theatre, English tea shops and gentlemen's clubs.
Although the grandeur of towns like Darjeeling, Dalhousie and Chail has been tarnished by unregulated construction and traffic pollution in recent decades, their cooler climes – celebrated in Bollywood films – have continued to attract honeymoon couples in large numbers.
Hoteliers however fear global warming is now sending them ever higher and further north in search of relief from the heat.
Many are now heading to Srinagar in Kashmir, where British officials and their families lived on Dal Lake's famous palatial house boats looking out over the Himalayan snow peaks.
"The weather is generally warmer this year, there has been a sudden rise in temperature this season. This has resulted in many tourists going to Kashmir and Ladakh which has cooler temperature. We are losing out on tourists to Kashmir because of increased temperature," said tour operator Atul Sharma.
"Normally, tourists would flock to Himachal in May, June and July to escape the heat in plains but this year the hotel occupancy has been around 70-80 per cent," he added.
According to Dr J C Kuniyal, a Scientist at G B Pant Institute of Himalayan Environment and Development, in Almora, another former British hill station, temperatures throughout Himachal Pradesh had risen partly because of increased tourism and traffic in the remote foothills.
His researchers had focused on the Kullu-Manali valley in Northern Himachal Pradesh where just under two million visitors every summer bring more than 4000 extra cars and jeeps.
"Such human activity in a fragile ecosystem will leave an negative impact on the local environment," he said.