As December 2025 begins, Kolkata is greeted by bright, sunny skies and pleasant temperatures, creating a deceptive calm over the city. However, this inviting weather masks a critical public health threat: dangerously polluted air. The city's air quality index (AQI-IN) soared to a severe level of 337 on Tuesday, casting a shadow over the clear winter days and prompting urgent advisories for its residents.
Sunshine and Smog: A Day of Contrasts
Today, Wednesday, December 3, 2025, Kolkata is set for a predominantly bright and sunny day with absolutely no chance of rainfall. The mercury is expected to climb from a cool morning low of 17.7°C to a warm afternoon peak of 28.7°C. The average temperature for the day will hover around a comfortable 22.7°C.
Moderate humidity levels of 35% and gentle winds up to 13.7 km/h will add to the day's pleasant feel. The evening will see a gradual cooldown, making it seemingly perfect for outdoor activities. Yet, the clear skies and dry, stagnant air are precisely the conditions that trap pollutants, leading to the ongoing air quality crisis.
Severe Air Pollution: A Deep Dive into the Numbers
The primary concern remains the hazardous air that Kolkata breathed yesterday. An AQI reading of 337 firmly placed the city in the 'Severe' category, indicating serious risk to health for all residents, not just vulnerable groups.
The pollutant breakdown reveals alarming concentrations:
- PM2.5 was recorded at 179 µg/m³.
- PM10 levels reached 228 µg/m³.
- Carbon monoxide (CO) was also high at 540 µg/m³.
All these values are significantly above the safe limits prescribed by health authorities. Exposure to such polluted air can trigger immediate health issues like breathing difficulties, throat irritation, and coughing, while also aggravating chronic respiratory and cardiovascular conditions over time. Despite today's sunshine, experts warn that air quality may linger in the 'Poor' to 'Very Poor' range due to a lack of strong wind or rain to disperse the pollutants.
Staying Safe: Recommendations for Kolkatans
While the weather is ideal for plans, caution is paramount. Health experts strongly advise sensitive groups—including children, the elderly, and individuals with asthma or heart conditions—to limit prolonged outdoor exposure. If going out is necessary, wearing a good-quality N95 or equivalent mask is crucial.
For the general public, here are key precautions:
- Schedule outdoor exercises like walking or cycling for later in the evening when temperatures are cooler, but remain aware of AQI updates.
- Stay well-hydrated throughout the day.
- Wear sunglasses to protect against the strong afternoon glare.
- Avoid areas with heavy traffic congestion to minimize direct exposure to vehicle emissions.
- Keep windows closed during peak pollution hours and consider using air purifiers indoors.
Weekly Outlook: Consistent Sun, Persistent Concerns
The weather forecast for the rest of the week promises stable and sunny conditions, ideal for winter outings but worrisome for pollution dispersion.
December 4: Sunny, high of 28.1°C, low of 16.3°C.
December 5: Clear skies, temperatures between 16.8°C and 28.4°C.
December 6: Slightly cooler, high of 27.6°C, low of 15.7°C.
December 7: Pleasant and sunny, max 27.5°C, min 15.4°C.
December 8: Partly cloudy, ranging from 15.8°C to 27.2°C.
This consistent dry spell underscores Kolkata's perennial winter battle with pollution, where calm winds and lower temperatures cause pollutants to settle close to the ground. The severe AQI of 337 serves as a stark reminder of this environmental challenge. Residents are encouraged to enjoy the pleasant weather but must prioritize monitoring daily AQI updates and taking necessary health precautions.
