Rudyard Kipling surely hadn’t accounted for Mamata Banerjee’s optimism about Calcutta and the vagaries of weather when he rather boldly declared that east and west “never the twain shall meet”.

Believe it or not, Kipling’s “city of dreadful night” is set to be more like his London this Christmas weekend, shamed by the Celsius slide in twin-city Calcutta, and without any evidence of London-loving Mamata’s Maradona-like hand-of-god lunge at the weather gods’ control panel.

We can picture you turning a cold nose up at us; so for authenticity’s sake do check the weather forecast, call the Met office or just Google global weather.

London’s weather has apparently become warmer and Calcutta’s colder than normal this winter to set up the possibility of a grand Christmas union at the stroke of 10 degrees Celsius.

All things remaining the same, the weekend forecast for the two cities reads thus: London 10 degrees Celsius maximum on Sunday, Calcutta 10 degrees minimum.

On Friday, the city’s maximum temperature also climbed down from 22.7 degrees Celsius the previous day to 21.2, which is a rare six degrees below normal.

According to the weatherman, there would be no let-up in the chill factor with the minimum temperature hovering between 10 and 12 degrees Celsius right till New Year’s Day. Saturday’s minimum reading is expected to be 11 degrees.

So while the lady at 30B Harish Chatterjee Street allows herself a chuckle at the happy coincidence of a mild London winter and an unusually cold one in Calcutta, don’t forget to raise a toast to what weather scientists call the “cold advection”.

“South Bengal is experiencing cold advection, or the entry of cold dry air from Jharkhand and the northern plains,” said Gokul Chandra Debnath, the director of the Regional Meteorological Centre in Alipore.

“When the maximum temperature dives five degrees or more below normal in winter, it is technically a cold day, minus the harshness of a cold wave. It’s perfect winter weather,” said an official of the Noida-based National Centre for Medium Range Weather Forecasting.

Not many seem to be complaining despite the winter clothing budget being stretched. “I am loving the cold, though it’s a pain getting out of bed in the morning. A bit like London, I guess,” chuckled Gautami Hazra, a second-year student at St. Xavier’s College.

But Trinamul MP Derek O’Brien refused to bite the biting-cold-like-London bait. “The Calcutta-London analogy is a genuine goal and those who take it facetiously are not giving the city a fair chance.... Calcutta is very much on course to becoming like London powered by a strong suburban railway network, an outstanding riverfront and a cultural hub,” he said.

Those tuning in to the economic forecast might, of course, argue that Mamata’s Bengal is too cold for investment anyway. Maybe there is a message blowing in the chilly winds for the chief minister who wants to turn her hometown into London.

Till such time investors warm up to Bengal, Calcuttans have a fun-filled festive week to look forward to. “This is going to be the coolest Christmas in more ways than one,” trilled Uma Chattoraj, a student of Calcutta University.

P.P. (Party pooper): Delhi is colder at seven degrees minimum, though that could be because control freak Kapil Sibal’s long arm has reached even the heavens to further subvert our federal system.

How can Calcutta become like London? Tell ttmetro@abpmail.com