Patients with chronic pain frequently report that changes in the weather influence their pain. This study investigated differences in the perceived influence of weather on pain among 558 chronic pain patients living in 4 cities (San Diego, California; Nashville, Tennessee; Worcester, Massachusetts; and Boston, Massachusetts) in the United States. Local climatologic data for each city were obtained from the National Climatic Data Center. All patients completed a weather questionnaire, and the information they provided was compared with demographic and weather variables. The majority of all patients believed that changes in the weather affected their pain. Pain patients who were younger and who had arthritis reported the most sensitivity to changes in weather. Weather sensitivity was unrelated to all other demographic variables and to geographic region. Cold and damp conditions were considered to influence pain the most. However, the perceived effect of weather on pain was not found to be related to regional climate. Thus, the belief that pain is worsened by living in a colder climate was not supported. An equilibrium theory of weather changes and pain is discussed. Further investigations are needed to identify the mechanisms involved in the effects of weather changes on pain.