Daily hay fever forecast in the Netherlands. Radio broadcasting of the expected influence of the weather or subjective complaints of hay fever sufferers.

The literature on local pollen counts and their significance for hay fever is reviewed and a system for forecasting hay fever is described. Such forecasts have been broadcast by radio in The Netherlands since 1977. The hay fever forecast takes the form of a prognosis (in terms of three grades) of the influence of the expected whether situation on tomorrow's course of the subjective complaints of hay fever sufferers. It is not a forecast of the pollen count. When the subjective complaints of about 150 hay fever patients were used as reference for evaluation, the forecasts proved to have been correct in 72, 85, and 88% of the cases in 1977, 1978, and 1979, respectively. The practical usefulness and the limitations of the system are briefly discussed, with emphasis on the principle that not the local pollen count but the weather should be taken as the main determinative factor for the expected subjective experiences in a group of hay fever sufferers in a certain region.