The World Health Organization (WHO) flagged elevated health risks associated with the strengthening El Niño climate phenomenon, with India among the countries facing significant risks from the resulting
shifts in temperature and rainfall patterns.
In its Global Public Health Situation Analysis- El Niño 2026, the WHO warned that El Niño can increase the likelihood of extreme heat, drought, flooding and changes in the spread of infectious diseases. The agency said the assessment is intended to help countries strengthen preparedness and health-system responses.
The warning comes as India is already seeing a rise in mosquito-borne diseases in some areas. In Delhi, August recorded 90 new dengue cases, taking the seasonal total to 311, while malaria cases rose from 17 in July to 53 in August, according to civic data cited in reports.
Why Could El Niño Increase Health Risks?
El Niño is a climate pattern caused by the periodic warming of surface waters in the central and eastern tropical Pacific Ocean. Warming alters atmospheric circulation and can disrupt weather patterns thousands of kilometres away.
For India, El Niño is generally associated with changes in monsoon rainfall and warmer conditions, although its precise impact varies depending on other climate factors. India’s Ministry of Earth Sciences has said El Niño conditions developed during 2026 and are expected to strengthen further, potentially reaching the “very strong” category later this year.
The WHO said changes in temperature, rainfall and humidity can affect the conditions in which mosquitoes breed and transmit diseases such as dengue and malaria.
How Does El Niño Affect Dengue And Malaria?
Mosquitoes are highly sensitive to their surrounding environment. Changes in temperature and rainfall can alter mosquito breeding, development and activity. Higher temperatures can speed up parts of the mosquito-borne disease transmission cycle, while irregular rainfall can create breeding sites when water accumulates in drains, containers, construction sites and other urban locations.
The relationship is not as simple as “more heat equals more dengue”. Different mosquito species and diseases respond differently to weather and outbreaks depend on several factors, including rainfall, humidity, water storage practices, sanitation and mosquito-control measures. The WHO has specifically noted that mosquitoes responsible for dengue and malaria are sensitive to temperature, rainfall and humidity, all of which influence the suitability of an environment for transmission.
What Is Happening In India?
India’s weather outlook is already being influenced by strengthening El Niño conditions. The Ministry of Earth Sciences said in August that El Niño was likely to persist through February 2027, while warning that its impact on the Indian monsoon depends on several other oceanic and atmospheric factors.
Separately, India is experiencing below-normal rainfall in September, following rainfall deficiencies earlier in the monsoon season. The combination has raised concerns over agriculture, water availability and food security.
