To analyze the impact of temperature on stroke mortality among residents in Wuhan city.

Stroke mortality data, meteorological data, and environmental monitoring data from 2014 to 2019 in Wuhan were collected. A distributed lag nonlinear model (DLNM) was used to assess the impact of temperature on stroke mortality. Stratified analyses were conducted based on gender and age to identify vulnerable populations.

The temperature-stroke mortality relationship in Wuhan exhibited an inverted “J” shape. High temperatures (P_97.5=32 °C) had the strongest immediate effect on stroke mortality on the same day, with the cumulative effect peaking on the 14^th day (relative risk [RR]=1.410, 95%CI: 1.219-1.630 compared to the minimum mortality temperature [MMT]). Low temperatures (P_2.5=1 °C) showed a delayed effect, beginning on the second day after exposure and reaching the maximum cumulative effect on the 21^st day (RR=1.553, 95%CI:1.161-2.079). Stratified analysis revealed that the cumulative effect of low temperatures on stroke mortality was the highest on the 21^st day for males (RR=1.786, 95%CI: 1.195-2.670), on the 7^th day for individuals aged <65 years (RR=1.607, 95%CI:1.151-2.243), and on the 14^th day for those aged ≥65 years (RR=1.627, 95%CI: 1.251-2.116). For high temperatures, the cumulative effect peaked on the 14^th day for males (RR=1.347, 95%CI: 1.104-1.645), individuals aged <65 years (RR=1.559,95%CI: 1.117-2.176), and those aged ≥65 years (RR=1.401, 95%CI: 1.204-1.631), while for females, it peaked on the 21^st day (RR=1.507, 95%CI: 1.188-1.912).

Both low and high temperatures can increase the risk of stroke mortality. High temperatures exhibit a more acute effect, while low temperatures show significant delayed and cumulative effects. Females andindividuals aged <65 years are at higher risk of stroke mortality under high temperatures, whereas males and those aged ≥65 years are more vulnerable under low temperatures. Protective measures should be strengthened for these high-risk populations.