Abstract Increasingly frequent extreme weather events are heightening the chances of mosquito‐borne diseases outbreaks, posing a notable threat to human health. However, how extreme weather influences the transmission dynamics of mosquito‐borne diseases remains poorly understood. Here, we integrate heat waves and effective precipitation as parameterization schemes into an SEI‐SEIR dynamic model to quantify their driving effects on chikungunya transmission. Based on the 2025 chikungunya fever outbreak in Foshan, the model successfully reproduced the observed transmission dynamics. Attribution analysis revealed that heat waves exerted a dual effect on transmission. Mosquito suitability declined by 9.7%, yet accelerated viral replication and altered human behavior generated a positive forcing that drove a net 76% increase in infected cases. Effective precipitation regulated outbreak scale nonlinearly, dispersed rainfall increased mosquito abundance by 205% and amplified transmission by 10.5%. Our research offered new insights into the impact of extreme weather on mosquito‐borne infectious diseases.