['To determine whether weather conditions explain the North-South gradient in multiple sclerosis (MS) mortality described in Spain.', 'The age-adjusted MS mortality rate by Spanish provinces from 1975 to 1998 was correlated with several climatic variables.', 'MS mortality was negatively correlated with minimum, average and maximum temperatures, the mean number of hours of sunshine, and the mean number of sunny days. A positive correlation was found with the average amount of rain. Most correlations disappeared after adjusting by latitude. However, MS mortality was associated with latitude after adjusting by climatic factors.'] Do [ Meteorological variables explain the North-South gradient in mortality from multiple sclerosis in Spain ]?