Heat index surge: Humidity is amplifying city’s summer

Bhubaneswar: Bhubaneswar has been reeling under unusually high real feel temperature (measurement that estimates how the weather actually feels to human skin) this summer, with the heat index crossing 50°C on several days even as the actual air temperature remained below 40°C.

The phenomenon points to the growing impact of humidity and urban factors on heat stress.Data shows that while the city temperature hovered between 35 and 40 degrees Celsius, the heat index — a measure of how hot it feels by combining temperature and humidity — often soared to extreme levels. On Sunday, the city recorded around 35°C at 11 am, but the heat index was as high as 44°C, making outdoor conditions uncomfortable and oppressive.Earlier this season on June 11, the heat index peaked at 51°C when the temperature was 36.4°C at 11.30 am. On June 8, the mercury stood at 36.2°C around the same time, but it felt like a scorching 52°C. On most days, relative humidity remained above 60%, significantly worsening discomfort levels.India Meteorological Department (IMD) Bhubaneswar director Manorama Mohanty attributed the phenomenon to a combination of temperature and humidity. “Being a coastal state, Odisha experiences high humidity due to moisture incursion from the Bay of Bengal into the coastal districts,” she said.

Experts said rapid urbanisation is compounding the problem. Asutosh Acharya, a chief climate scientist at Aurassure, said Bhubaneswar often feels like an oven due to trapped humid air. “Moisture-laden air from the sea forms a hot, damp blanket over the city. At the same time, concrete roads and buildings absorb heat during the day and release it at night, intensifying the urban heat island effect,” he said.He added that dense building construction also disrupts natural wind flow.

“Tall buildings block breezes, leaving the air stagnant. Without airflow, sweat cannot evaporate effectively, which directly raises the heat index. This can make a 35°C day feel like 50°C,” Acharya explained.Former IMD Bhubaneswar director Sarat Chandra Sahu said humidity levels remained above 60% during peak daytime hours, particularly between 10 am and 4 pm when heat index is calculated. He pointed out that weak pre-monsoon activity further aggravated the situation.“The absence of widespread nor’wester rainfall and weak monsoon currents after onset over the Andaman Sea resulted in low-intensity rainfall. Additionally, lack of southwesterly winds from the Arabian Sea and dominance of northwesterly winds contributed to rising humidity in coastal areas,” Sahu said.With monsoon yet to fully stabilise, experts warn that such high heat index conditions could continue to pose health risks, even when temperatures appear moderate.