NEW DELHI: Dengue and malaria normally peak after monsoon, but Delhi-NCR data show continued cases into late autumn and early winter some years.
Vector-borne diseases such as dengue and malaria are classically associated with the rainy season in India, when standing water provides breeding grounds for mosquitoes. Yet public health officials in Delhi NCR routinely record cases well after the monsoon ends, sometimes into November and December, prompting questions about seasonality and risk in cooler months. Recent local surveillance and media reports from Delhi, Noida and Greater Noida document hundreds of dengue and several hundred malaria infections during the post-monsoon period in 2025, with spot outbreaks prompting intensified anti-larval drives and fogging. Understanding why cases can persist into winter, and when they decline, is essential for targeted prevention.
In short, while peak transmission is post-monsoon, residual breeding, urban microclimates, stalled vector control activities and human behaviour can sustain transmission into the cooler months.
Delhi NCR Case Reports: Dengue And Malaria Cases Lower Than Last Year
Official surveillance and recent alerts indicate that vector-borne disease transmission in Delhi NCR remains dynamic.
The National Vector Borne Disease Control Programme (NVBDCP) and the Integrated Disease Surveillance Programme (IDSP) publish district-level case counts; NVBDCP’s annual reports and IDSP alerts confirm that dengue and malaria continue to be reported outside the core monsoon months in many urban districts.
Local public-health reporting in late 2025 showed Delhi recording several hundred dengue cases and a few hundred malaria cases through October-November, and Noida-Greater Noida reporting similar clusters that prompted intensified fogging and anti-larval operations. Municipal alerts and press briefings documented house inspections and fines for breeding sites.
The NCDC’s Delhi technical documents note that with climate variability transmission windows are expanding; some modelling suggests Delhi could see 10-12 months of potential malaria transmission as temperatures and rainfall patterns shift.
These numbers do not mean year-round surges everywhere. Rather, they reflect localized pockets where breeding conditions persist or control measures lapse.
Why Cases Can Persist Or Rise In Cooler Months
Residual Breeding Sites in Urban Areas
Aedes aegypti (dengue) breeds in small, artificial containers (pots, tyres, rooftop tanks) that can hold water long after rains stop. If municipal or household clean-ups are incomplete, breeding continues. NVBDCP emphasises source reduction as cornerstone control.
