Abstract
Although predicting the first day of continuous Japanese cedar pollen emission is important information for cedar pollinosis patients, the reliability of predicting this based on the cumulative daily highest temperatures and mean temperature from January 1st is poor in regions with a large snowfall, because snowfall and low temperatures during the winter affect the growth of the cedar male flowers. Therefore, we investigated the appropriate initial date for recording the temperatures to predict the first day of continuous cedar pollen emission in Hirosaki City. In addition, we also devised a minimum temperature standard for calculating the cumulative temperature, which is the most useful data for such a prediction. The results indicated that the initial date for temperature recording should be set at January 21st or February 1st and such predictions were possible from the days in which the daily highest temperature exceeded 3° from the initial date. The amount of snowfall had no effect on the results, thus indicating this to be a useful method for predicting the first day of continuous Japanese cedar pollen emission in regions with a large snowfall.
