Understanding the associations of air pollutants and temperature with the incidence of mumps, and exploring the interaction effects of heat index (HI) and air pollutants, are crucial for disease intervention under the context of climate change. This time-series study was conducted in Jining city using data on daily mumps cases, meteorological factors and air pollutants obtained from 2015 to 2021. Distributed lag models combined with quasi-Poisson regressions were applied to examine these associations. The findings indicated a heightened risk of mumps in correlation with elevated exposure to PM