Why are Odisha’s twin cities of Bhubaneswar, Cuttack so hot and humid?

Odisha's twin cities, Bhubaneswar and Cuttack, endure some of the most uncomfortably hot and humid weather in India. According to British air quality analysis firm HouseFresh, Bhubaneswar's humidity reached 99.1% in 2022, while Cuttack recorded 98.9%, placing them just behind Patna (99.2%) as India's second and third most humid cities.

While this might appear as a straightforward consequence of their tropical location, the reality is significantly more complex. A combination of natural geography, evolving meteorological patterns, and unrelenting urbanisation drives the increasingly inhospitable climate experienced in these cities.

Rising Humidity: Hard Numbers

In 2024, weather data from the India Meteorological Department (IMD) revealed that Bhubaneswar frequently crossed 80% humidity thresholds even in non-monsoon months, peaking at 96% on multiple April nights.

Similarly, Cuttack saw consistent early morning humidity levels between 92% and 97% during the March-May period. Daytime temperatures simultaneously breached 40 degrees Celsius, raising the heat index to extreme levels, thereby making outdoor activity difficult and heat stress increasingly common.

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Urban Heat Island Effect: A Man-Made Amplifier

Urbanisation has played a decisive role in intensifying the heat. Bhubaneswar's maximum land surface temperature increased from 36.43 degrees Celsius in 1990 to 43.25 degrees Celsius in 2020, according to studies published by the Current World Environment Journal. Cuttack followed a similar trend, rising from 35.5 degrees Celsius to 41.4 degrees Celsius.

Urban Heat Island (UHI) effects are significant:

• Bhubaneswar is approximately 0.75 degrees Celsius warmer than the surrounding rural areas.
• Cuttack shows a 1.22 degrees Celsius urban-rural differential.
• Nighttime UHI rates are rising at 0.18 degrees Celsius/decade (Bhubaneswar) and 0.13 degrees Celsius/decade (Cuttack).

These increases are linked to:

• Loss of green spaces: Bhubaneswar lost 89% of dense vegetation between 2001 and 2020.
• Widespread use of concrete and asphalt, which store and re-radiate heat.
• Dense construction and high-rise buildings that trap air and block ventilation.
• High vehicular activity and cooling devices releasing waste heat.

Geographical Setting and Coastal Proximity

Located near the Tropic of Cancer, Bhubaneswar and Cuttack receive intense solar radiation for most of the year.

Despite lying 60 to 80 kilometres inland, their proximity to the Bay of Bengal means a consistent influx of warm, moisture-laden winds, especially during pre-monsoon and monsoon periods. This ensures that humidity levels remain elevated year-round.

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Topographical and Meteorological Drivers

The cities’ flat terrain and low elevation fail to facilitate cooling through orographic processes. During summer, the pre-monsoon trough over eastern India encourages the formation of low-pressure zones, drawing more humid air inland. These systems bring in warm moisture even before the actual onset of the monsoon.

Daily sea and land breezes further influence the weather. Daytime onshore winds carry maritime moisture, while night-time offshore winds struggle to clear built-up heat and humidity trapped within the concrete-heavy cityscape.

Climate models suggest that Odisha could witness an average temperature rise of 1.5 degrees Celsius to 2 degrees Celsius by 2050, with significant implications for humidity levels, disease burden, and urban livability.

With humidity levels among the highest in India and temperatures steadily climbing, these twin cities present a stark warning about the future of coastal urban centres. A science-led, sustainable approach to development is no longer optional but compulsory.