The fish remains sampled from archaeological sites are generally the result of human food refuse; therefore, the study of retrieved fish scales may provide reliable information on the season of capture and on paleoclimate and paleoenvironmental changes. Among Western European freshwater fishes, the grayling, Thymallus thymallus¸ has the most easily recognizable scales and is a commonly recovered species from Palaeolithic contexts. This study, therefore, is based on the growth pattern analysis of modern and archaeological scales from grayling specimens. The modern specimens were collected monthly in France (n = 22), Switzerland (n = 16), Finland (n = 20) and Sweden (n = 10). Scale growth patterns were measured using numerical analysis to a high accuracy. The results showed that the archaeological population of grayling is closer to the present Finnish population. Furthermore, the comparison of seasonal growth patterns between current and archaeological European populations demonstrated that graylings were normally captured during the spring at Le Taillis des Coteaux Magdalenian site. This type of approach can be used to understand environmental conditions at a low spatial scale and also to help identify fishing seasons during archaeological periods. Copyright © 2017 John Wiley & Sons, Ltd.