Kolkata Weather Today, September 17, 2026: Monsoon Makes a Fresh Comeback, Thunderstorms and Gusty Winds Likely

KOLKATA: Kolkata is likely to experience another spell of unsettled weather on Thursday, September 17, as monsoon activity once again strengthens over southern West Bengal. After a relatively warm and humid spell, the city is expected to see partly cloudy to cloudy skies, rain and thunderstorms at intervals through the day. The latest forecast from the India Meteorological Department’s Regional Meteorological Centre in Kolkata indicates a maximum temperature of around 33°C and a minimum of about 28°C for the Alipore observatory.

The morning has begun on a warm and humid note, but the weather is expected to become increasingly unstable as the day progresses. Independent hourly forecasts also indicate a growing possibility of thunderstorms and showers from the late morning onward, with rain chances remaining significant around midday.

Clouds to dominate, rain may interrupt the day

The most noticeable change in Kolkata’s weather today is the return of convective activity. The IMD’s city forecast has specifically indicated thunderstorms with rain, with the possibility of lightning and gusty winds reaching around 30–40 kmph.

This means the city could see a familiar monsoon pattern: periods of sunshine or heavy cloud cover followed by a sudden spell of rain and thunder. Such showers may not be uniform across Kolkata, with some neighbourhoods receiving a brief spell while others could experience comparatively heavier rain.

The weather may also feel considerably warmer than the actual thermometer reading because of high humidity. A combination of moisture-laden air, cloud cover and intermittent sunshine is likely to keep discomfort levels elevated, particularly before rainfall brings temporary relief.

IMD flags thunderstorm activity over Gangetic West Bengal

The regional weather office has issued a Day 1 warning for Gangetic West Bengal for thunderstorm, lightning and squall-related activity on September 17. The warning does not extend into the following days at the same level, with no corresponding warning listed for September 18 onward in the latest subdivision bulletin.

The broader weather pattern is significant because the IMD has forecast widespread rainfall, thunderstorms and gusty winds across several parts of the country during September 17–22, with West Bengal among the regions expected to experience unsettled conditions.

For Kolkata, however, the immediate concern is more about intermittent thunderstorms and rain rather than a prolonged spell of extremely heavy rainfall. The city’s forecast currently points towards rain and thunderstorm activity, while the IMD city bulletin does not indicate a heavy-rain warning for Kolkata itself today.

A humid September day could turn stormy

Kolkata’s September weather often carries the dual character of late monsoon and approaching autumn. While the calendar moves towards the post-monsoon period, moisture remains abundant over the region. This can create conditions in which intense but short-duration thunderstorms develop, particularly when daytime heating combines with atmospheric moisture.

Thursday’s forecast reflects precisely this kind of transition. The city may begin with relatively manageable conditions before clouds build and thunderstorms become more likely later in the morning and afternoon. An hourly forecast currently places the probability of thunderstorms substantially higher from around late morning into the early afternoon.

Weather may remain unsettled beyond Thursday

The change is not necessarily restricted to a single day. The IMD’s Kolkata city forecast indicates partly cloudy conditions with a possibility of moderate rain or thunderstorms on September 18, followed by generally cloudy skies and light rain possibilities over the subsequent days.

This suggests that Kolkata could remain under a humid and occasionally wet weather regime even as the intensity of the immediate thunderstorm activity fluctuates.

Across South Bengal, several districts are also expected to receive light to moderate rainfall, while some areas could experience thunderstorms and gusty winds. The return of rainfall is therefore being seen as a broader regional weather shift rather than an isolated Kolkata phenomenon.

What Kolkata residents can expect today

For commuters, office-goers, students and those travelling across the city, the key weather factor today will be uncertainty. A dry morning does not necessarily mean the rest of the day will remain dry. Sudden cloud development, lightning and gusty winds could lead to short-lived disruptions, particularly during thunderstorm activity.

Motorists should be particularly cautious during heavy showers because sudden reductions in visibility and water accumulation on roads can make traffic movement slower. People outdoors should also avoid exposed locations during lightning or strong winds.

For Kolkata, September 17 is shaping up to be a day when the monsoon refuses to completely step aside. Temperatures will remain around the low 30s, humidity will continue to make the air feel oppressive, and thunderstorms or rain could provide sudden breaks from the heat. With the IMD flagging thunderstorm and lightning activity over Gangetic West Bengal today, residents should keep an eye on short-term weather updates before making outdoor plans.