Reports indicate that weather conditions may affect some symptoms of rheumatoid arthritis (RA) but not the disease itself. Eighty-eight patients living in the marine climate of the Dutch coastal provinces scored their pain symptoms daily during a full year. Correlation analyses of monthly patient averaged pain scores against each of 6 weather factors indicated that RA pain associates positively and quite significantly (p less than 0.01) with temperature and with vapour pressure, negatively and significantly (p less than 0.02) with relative humidity and not with any of the other factors. The fact that the relation between the temperature/vapour pressure complex and RA pain is stronger in summer than in winter is discussed.