This 'thermic law' is one of the oldest propositions in criminology. Modern research produces contradictory findings: some studies support a seasonal pattern of homicide while others reject such a pattern. A review of studies on this issue and an analysis of Uniform Crime Reports data and data on homicide in Baltimore from 1974 to 1984 are undertaken in order to resolve the issue. The contradictory results are not explained by differences in definitions nor by differences in data or methodology, nor are they explained on the basis of regional differences or an urban bias critical to the results obtained. The nature of the question asked, however, is critical to the results obtained, and the conclusion reached is that there is no season to homicide. The months of December, July, and August are significantly more likely to be among the months in which homicide is high for any given year, but the number of homicides during those months may not be significantly higher than in other months. 7 tables, 7 footnotes, and 43 references. (Author abstract modified)