<p>Karnataka is witnessing at least nine to 13 additional warm nights compared to three decades ago. This is not only affecting people’s productivity but also causing serious health issues.</p>.<p>According to a report — How Extreme Heat is Impacting India: Assessing District-level Heat Risk—by the Council on Energy, Environment and Water (CEEW), at least 35 factors, including increased humidity, depletion of green cover, heat waves, and the formation of urban heat islands, are increasing night temperatures.</p>.<p>The report says that 93% of Karnataka’s districts are in the very high and high heat risk categories. Coastal districts and three of the Malnad districts are in the very high risk category.</p>.<p>Vishwas Chitale, Fellow at CEEW, said: “The rise in very warm nights is most evident in densely populated districts. Over the last decade, Bengaluru has witnessed 11 additional warm night days. Similarly, Mysuru, Mangaluru, Shivamogga, and Hubballi-Dharwad, which are witnessing urbanization, experienced warmer nights. This trend is largely driven by the urban heat island effect, where heat absorbed during the day is released at night, keeping cities warmer.”</p>.<p>Between 1981 and 2022, heat extremes in India have increased linearly, contributing to major heatwaves in 2013, 2016, 2019, 2022, and 2024, the report notes.</p>.<p>In the last decade, very warm nights have increased faster than very hot days. Nearly 70% of India’s districts experienced five or more additional very warm nights per summer (March to June), while only around 28% saw a similar increase in very hot days.</p>.<p>“Warmer nights are particularly concerning as they make it harder for the body to cool down and recover from daytime heat. This increases the risk of heat exhaustion, heatstroke, hypertension, cardiovascular diseases, and renal disorders,” he added.</p>.<p>Chitale said that extreme heat now poses a risk to 57% of Indian districts—home to 76% of the population.</p>.<p>In Karnataka, several districts—including Dakshina Kannada, Udupi, Uttara Kannada, Vijayapura, Belagavi, Bidar, Kalaburagi, Mysuru, Bagalkot, and Shivamogga—fall under the very high-risk category, while Bengaluru Rural and Chikkaballapura are among those in the moderate-risk category.</p>.<p>The report says there is also a 3% to 4% increase in relative humidity across the State which makes people feel more sultry and exhausted, even though the temperature might have risen just one to three degrees Celsius above normal.</p>.<p>N Puviarasan, head of the Bengaluru Meteorological Centre, said that the India Meteorological Department (IMD) currently records maximum and minimum temperatures. “We are not separately analysing long-term trends in night-time temperatures. Such conclusions require detailed comparative studies over time,” he said.</p>.<p>He added that urbanisation and depletion of green cover were major contributors to the formation of local heat islands and need urgent attention.</p>
<p>Karnataka is witnessing at least nine to 13 additional warm nights compared to three decades ago. This is not only affecting people’s productivity but also causing serious health issues.</p>.<p>According to a report — How Extreme Heat is Impacting India: Assessing District-level Heat Risk—by the Council on Energy, Environment and Water (CEEW), at least 35 factors, including increased humidity, depletion of green cover, heat waves, and the formation of urban heat islands, are increasing night temperatures.</p>.<p>The report says that 93% of Karnataka’s districts are in the very high and high heat risk categories. Coastal districts and three of the Malnad districts are in the very high risk category.</p>.<p>Vishwas Chitale, Fellow at CEEW, said: “The rise in very warm nights is most evident in densely populated districts. Over the last decade, Bengaluru has witnessed 11 additional warm night days. Similarly, Mysuru, Mangaluru, Shivamogga, and Hubballi-Dharwad, which are witnessing urbanization, experienced warmer nights. This trend is largely driven by the urban heat island effect, where heat absorbed during the day is released at night, keeping cities warmer.”</p>.<p>Between 1981 and 2022, heat extremes in India have increased linearly, contributing to major heatwaves in 2013, 2016, 2019, 2022, and 2024, the report notes.</p>.<p>In the last decade, very warm nights have increased faster than very hot days. Nearly 70% of India’s districts experienced five or more additional very warm nights per summer (March to June), while only around 28% saw a similar increase in very hot days.</p>.<p>“Warmer nights are particularly concerning as they make it harder for the body to cool down and recover from daytime heat. This increases the risk of heat exhaustion, heatstroke, hypertension, cardiovascular diseases, and renal disorders,” he added.</p>.<p>Chitale said that extreme heat now poses a risk to 57% of Indian districts—home to 76% of the population.</p>.<p>In Karnataka, several districts—including Dakshina Kannada, Udupi, Uttara Kannada, Vijayapura, Belagavi, Bidar, Kalaburagi, Mysuru, Bagalkot, and Shivamogga—fall under the very high-risk category, while Bengaluru Rural and Chikkaballapura are among those in the moderate-risk category.</p>.<p>The report says there is also a 3% to 4% increase in relative humidity across the State which makes people feel more sultry and exhausted, even though the temperature might have risen just one to three degrees Celsius above normal.</p>.<p>N Puviarasan, head of the Bengaluru Meteorological Centre, said that the India Meteorological Department (IMD) currently records maximum and minimum temperatures. “We are not separately analysing long-term trends in night-time temperatures. Such conclusions require detailed comparative studies over time,” he said.</p>.<p>He added that urbanisation and depletion of green cover were major contributors to the formation of local heat islands and need urgent attention.</p>