In early April 2025, an intense heat wave swept across India and Pakistan, with temperatures soaring significantly above seasonal averages. On April 8, Barmer in Rajasthan, India, recorded a peak temperature of 46.4°C (115.5°F), surpassing typical April highs by over 6°C. This extreme heat has led to severe health crises, agricultural disruptions, and underscores the escalating impact of climate change in South Asia.

The heat wave commenced in early April 2025, with temperatures in both India and Pakistan reaching 5-8°C above seasonal norms. The India Meteorological Department (IMD) had anticipated these conditions, advising citizens to prepare for an "above-normal number of heatwave days" throughout April. Meteorologists have linked the severity and early onset of this heat wave to broader climate change patterns affecting the region. Climate scientists have identified the Indian subcontinent as particularly vulnerable to thermal extremes, with projections suggesting that by mid-century, parts of India could experience temperatures exceeding human survivability thresholds.

In India's capital of New Delhi, temperatures exceeded 40°C multiple times during April, marking departures of up to 5°C from average seasonal values and impacting the city's more than sixteen million residents. The neighboring state of Rajasthan registered extreme temperatures of 44°C by mid-April. Barmer, a city in Rajasthan, recorded a peak temperature of 46.4°C on April 8, representing a deviation of more than 6°C above average April maximum temperatures for the region and breaking the decades-old April temperature records for the region. In Jaipur, the capital of Rajasthan, temperatures exceeded 40°C for five consecutive days beginning April 6. The city registered a peak temperature of 43.0°C on April 9, approximately 5°C above typical April high temperatures for the location. On April 8, approximately thirty weather stations spread throughout India documented temperatures exceeding 43.0°C, with many areas classified as experiencing severe heat wave conditions according to official meteorological standards.

The extreme heat has led to severe thunderstorms in eastern India, particularly in Bihar, resulting in at least 19 fatalities over a two-day period. Agricultural communities in northwestern India reported widespread disruptions to farming activities and increasing cases of heat illnesses. Fieldworkers described symptoms including dehydration, nausea, and dizziness when attempting outdoor labor during peak temperature periods. In Bihar, agricultural products including mango, lychee, and wheat crops suffered extensive damage just weeks before scheduled harvests.

In Pakistan, cities like Jacobabad and Sibi in Sindh province recorded temperatures of 47°C (116.6°F) on April 15, marking the highest temperatures in the Northern Hemisphere on that day. The southwestern province of Balochistan experienced particularly severe conditions, with inhabitants of Dera Murad Jamali city reporting that the thermal stress arrived with unexpected intensity. Extended power outages lasting up to sixteen hours daily exacerbated challenges against living conditions for many residents, eliminating access to cooling systems during critical high-temperature periods. The province faced additional water security challenges due to minimal rainfall and significant drought conditions during the winter months preceding the heat wave. Pakistani farmers reported accelerated crop development followed by reduced yields as plants struggled to cope with thermal stress and water scarcity during critical growth stages.

In India, several regions in Gujarat state were placed under orange alert status on April 10, indicating heat wave conditions in multiple districts and heightened probability of heat-related illnesses. Residents of impacted areas were instructed to avoid heat exposure while taking active measures against dehydration. The Uttar Pradesh Government issued directives for hospitals to prepare for increased cases of heat-related illnesses. The state administration also alerted veterinarian teams and animal shelters to remain vigilant and ensure adequate shelter and water provisions for livestock and other animals under their care.

This heat wave is part of a series of extreme temperature events in the region over the past decade. Notably, the 2015 heat wave resulted in over 2,500 deaths in India and more than 1,100 in Pakistan. In 2016, India recorded its highest-ever temperature of 51.0°C (123.8°F) in Phalodi, Rajasthan. The 2022 heat wave was characterized by the hottest March in the subcontinent since 1901, with temperatures in Pakistan's Nawabshah reaching 49.5°C.

Studies have indicated that climate change has significantly increased the likelihood and intensity of heat waves in the region. A Met Office study found that climate change makes record-breaking heatwaves in northwest India and Pakistan 100 times more likely. Another study concluded that human emissions of greenhouse gases made the 2022 heat wave both about 1°C hotter and more likely to occur, with the probability of such an event increasing by a factor of 30.

The escalating frequency and severity of heat waves in South Asia underscore the urgent need for comprehensive climate adaptation and mitigation strategies. The disproportionate impact on vulnerable populations, including agricultural workers and low-income communities, highlights the necessity for targeted interventions to protect public health and ensure food security in the face of a changing climate.