Season and location have previously been shown to be associated with differences in the microbiota of raw milk, especially in milk from pasture-based systems. Here we further advance research in this area by examining differences in the raw milk microbiota from several locations across Ireland over 12 months, and by investigating microbiota associations with climatic variables and chemical composition. Shotgun metagenomic sequencing was used to investigate the microbiota of raw milk collected from 9 locations (n=241). Concurrent chemical analysis of the protein, fat, lactose, total solids, nonprotein nitrogen (NPN) contents and titratable acidity (TA) of the same raw milk were performed.