Kolkata (Calcutta) weather in September

Sundarbans-forum threads on rain describe September as the waning phase of the monsoon across Bengal, conditions capable of swinging between a settled stretch and a properly wet one depending on the year. Posters call the mangrove waterways and boat-based wildlife viewing largely unaffected by a passing shower, most of a multi-day cruise continuing regardless of a spell of rain. Regulars are direct spotting a tiger is never guaranteed, posters recommending visitors treat the wider mangrove ecosystem and birdlife as the real draw rather than fixating on one sighting. Posters describe humidity as genuinely high, breathable clothing and real bug protection standing advice regardless of forecast. Regulars call winter the more favored season, September still entirely workable for travelers comfortable with humid, unpredictable conditions. The record: 31.1C days feeling like a punishing 37C, 25.9C nights, an extraordinarily high 236mm across over 25 days and 87 percent humidity.

Regulars are blunt that this is genuinely hot, humid, endurance-test weather, with daytime highs commonly cited in the mid-30s Celsius, and several specifically steer first-time visitors toward October-February instead. Our row backs the hot read, 34.8C reading as a rough 39C, over 25.7C nights, with 64.9mm of rain across 8.4 days. For anyone visiting anyway, regulars are specific that a Hooghly river cruise is far more pleasant scheduled for evening or early morning, when a breeze off the water and cooling temperatures make it comfortable, rather than in the middle of a hot afternoon. AC rooms are treated as close to mandatory rather than a nice-to-have. The record: humidity 71 percent, 11.4 hours of sun and AQI 138.

November to February is the window regulars recommend and March is the month after it: hotter, they say, but not yet unbearable, with evenings that are still genuinely pleasant. Our row gives 32.2C reading as 36C by day and 22.9C at night, so their split is the right way to plan the day. The little rain there is falls mainly after dark - 36mm across 6 days. The cost of a late dry-season month is the air: AQI 138, worse than November's 117 and still without a monsoon to clear it. Anything walked belongs to the morning or the evening from here until the rains. The record: humidity 69 percent, 10.7 hours of sun and a 12.2 kph wind.

November opens the season regulars recommend - through to February the rain stops, the humidity becomes tolerable and the city is comfortable, which after a monsoon that floods it is the whole point. Their comfortable range of 18 to 22C is the morning and evening rather than the day: our row gives 28.9C reading as 31C, with nights at 20.1C, and rain down to 31mm across 2.5 days. The cost of the dry season is in our air column, AQI 167 - the still, rainless months are also the ones without anything to wash the air. The big pujas move with the lunar calendar into October or November, so check the year's dates before booking. The record: humidity 75 percent and 9.4 hours of sun.

Kolkata-forum threads put December squarely in the best window of the year, the November-to-February stretch once the heat and the humid season have subsided, with days pleasant enough for sightseeing and nights genuinely cool. December carries its own calendar too: the Park Street Christmas Carnival lights up the street through New Year's, and the city's international book fair draws visitors from well beyond West Bengal. The record backs the pleasant read: 25C days feeling like 26C, 16C nights, essentially none at under two days, and 9.3 hours of sun. What the forum threads skip past: AQI runs 166 here, one of the worst months of the year for air, a haze the winter stillness does nothing to clear.