Abstract: Temperature variability, particularly diurnal temperature range (DTR), has been linked to mortality, yet evidence from low- and middle-income settings remains limited. We analyzed 188,039 deaths in Ningbo, China (2014–2018) using a time-series design with a distributed lag non-linear model. A J-shaped DTR–mortality curve was observed, with a city-specific minimum-mortality DTR (MMDTR) of 15.3 °C. Both low and high DTR increased mortality risk. Cause-specific effects were largest for endocrine, nutritional, and metabolic diseases (higher excess risk 18.9%), followed by circulatory (5.7%) and respiratory (4.2%) deaths. Females and older adults were more vulnerable. Children showed elevated risks that were not statistically significant and were imprecisely estimated (wide confidence intervals). Overall, 22.7% (~42,711) of deaths were attributable to DTR, largely from the common low-to-moderate DTR range (20.4%;~38,369), despite steeper relative risks at the upper tail. Both low- and high-DTR conditions merit attention; preparedness for high-DTR episodes may need to increase with climate change, while routine protection during frequent low-DTR days could yield substantial benefits, especially for females and older adults, and children, who showed high point estimates despite wide confidence intervals.

Keywords: Climate change; All-cause mortality; Cause-specific mortality; Diurnal temperature range; Distributed-Lag nonlinear model

基金资助：This work was supported by grants from the CIRP (China Institute for Radiation Protection) Open Fund of Radiation Protection Laboratories (ZFYFSHJ-2024003) and the Fundamental Research Funds for the Central Universities of China(2023jbkyzx002).

原文链接： https://doi.org/10.1007/s11869-025-01876-4