Abstract: Objective To explore the impact of ambient temperature on the incidence of mumps in Dongguan, Foshan, Guangzhou and Shenzhen in Guangdong Province. Methods Daily meteorology data and mumps cases from 2005-2018 were collected in Dongguan, Foshan, Guangzhou and Shenzhen City. Then the city-specific relationship between ambient temperature and mumps was assessed based on distributed lag non-linear model, controlling the time trend, day of the week, relative humidity and pressure for confounding factors. Finally, the cold and heat effects of low temperature （the 5^th percentile of daily temperature） and high temperature （the 95^th percentile of daily temperature） on the incidence of mumps in different age and genders were compared.Results There were 212 109 mumps cases reported in four cities during 2005-2018. The daily median temperature was 23 ℃~25 ℃. The overall effect of ambient temperature on the incidence of mumps in four cities showed an inverted S-shape. The cold effect was slightly higher for male （RR=1.131, 95%CI： 1.018-1.256） than female （RR=1.093, 95%CI： 0.955-1.251）, while heat effect was slightly higher for female （RR=1.014, 95%CI： 1.001-1.026） than male （RR=1.009, 95%CI： 0.997-1.022）,but there were no statistical significance （P>0.05）. The cold effect （RR=1.476, 95%CI： 1.300-1.677） and heat effect （RR=1.020, 95%CI： 1.006-1.034） were higher for adolescents aged 6-17 years old, the difference was statistically significant （P<0.05）. Conclusion The relationship between ambient temperature and the incidence of mumps is non-linear. Ambient temperature may be an important predictor of the incidence of mumps. Adolescents aged 6-17 years old are more sensitive to ambient temperature, whom more attention should be paid to.

Key words: Ambient temperature, Mumps, Distributed lag non-linear model