Prediction of the pollen season with a cumulated activity method

An attempt is made to forecast the start, the peak and the end of the pollen season. The cumulated activity method, a development of the temperature sum method, is used. Temperature (T) is transformed to activity (A) by the formula A = 2** ((T+g)/(10+h))-k where g, h and k are parameters (** indicates exponentiation). The method is tested using pollen and weather measurements from Stockholm for the years 1973–88. Of the eight pollen types tested, the best results are gained for Ulmus, Betula and Pinus, with a prediction precision varying between three and six days. The method was less relevant for Alnus and Quercus and not satisfactory for Corylus, Poaceae and Artemisia.