The effect of the change in air temperature on the number of newborns in Vienna 1984–99


Thomas Waldhoer, PhD, Division of Epidemiology, Institute of Cancer Research, University of Vienna, Borschkeg. 8a, A-1090 Vienna, Austria.


The number of daily births depends on a wide range of sociodemographic, temporal as well as many other mostly unknown factors, resulting in non-random patterns. We tested the hypothesis of the influence of the change in air temperature on the daily number of all newborns in Vienna (n = 254 797) in the period 1984–99 (n = 5843 days). We found a significant association of sudden changes in temperature with the daily number of births. The observed effect is responsible for up to 0.27% of the explained variation in the regression model.