Mosquito-borne diseases, such as malaria, are evolving as cities expand and the climate warms. One species of mosquito, Anopheles stephensi, now thrives in urban areas. Temperature and humidity both affect how mosquitoes grow and how easily the malaria parasite can spread—but the role of humidity is not well understood.
In this study, we measured indoor and outdoor temperature and humidity in two Indian cities, Ahmedabad and Surat. Using satellite data and information about buildings, vegetation, and land surfaces, we created detailed maps of local climate conditions at a very fine scale. We then used a model to predict how temperature and humidity shape the risk of malaria transmission in different parts of each city.
Our results show that areas with higher humidity were more suitable for malaria transmission, particularly during and after the rainy season. During the hottest months, the risk was lower overall, but it still existed in cooler, more humid pockets. We also found that including humidity in our model gave different results compared to using temperature alone.
This study shows how combining ground data and satellite information can help cities identify areas most at risk and plan more targeted mosquito control efforts.