Dengue has emerged as a major public health concern in Nepal, with increasing geographic spread and recurrent seasonal outbreaks over recent years. While climatic factors such as temperature, rainfall, and humidity are known to influence dengue transmission, limited research in Nepal has systematically examined their delayed effects using national-level data.
This study investigates the time-lagged relationships between climate variables and monthly dengue incidence across 75 districts of Nepal aggregated nationally from 2022 to 2025. A retrospective time-series design was employed using official epidemiological records and meteorological data. Pearson correlation analysis was conducted using same-month and lagged climate variables (one- and two-month lags). The findings revealed weak same-month associations but substantially stronger correlations when rainfall and temperature were lagged by one to two months. Rainfall demonstrated the strongest delayed relationship with dengue incidence, indicating a 1-2month lag effect consistent with mosquito breeding and viral incubation cycles. Humidity showed a relatively stronger immediate association. 
These results highlight the importance of incorporating lagged climate indicators into early warning systems. Understanding delayed climate effects can support more proactive dengue preparedness, improve resource allocation, and strengthen climate-sensitive public health planning in Nepal.