ABSTRACT To achieve the goal of “peak carbon dioxide emissions and carbon neutrality,” China has proposed significant measures to promote green technological innovation. Though abundant research has confirmed the positive impact of green innovation on the environment, whether environmental factors reciprocally influence green innovation remains insufficiently explored. This study delves into the influence of extreme temperatures on urban green innovation, utilizing panel data from 287 prefecture‐level cities in China spanning from 2003 to 2019. Results indicate that extreme temperatures significantly impede the development of urban green innovation, with a series of robustness tests affirming the reliability of this effect. We find that this effect is transmitted through both the “inequality exacerbation effect” and the “industrial production inhibition effect.” In addition, the dampening effect is more pronounced in cities in the eastern part of the country, in smaller cities, and in cities with low river densities. This paper further finds that extreme heat is the main factor that causes extreme temperature to inhibit green innovation in cities. Moreover, extreme temperatures also had a consistent inhibitory effect on the overall innovation capacity of cities.